P was very good with identifying parts with part numbers as Flack's post notes.
Always look for stamped or cast part numbers, then search on the parts lists for model use. ie, reverse lookup so to speak. May have to check several editions to get right year.
It's easy to swop hubcaps so what comes with it or in the trunk after this many years, may not always be what it was born with, if going for correctness, or just ID what one has at hand.
Another trick is to search original photos in model information, internet, but hit or miss and takes time.
Lots of handy info at your finger tips on the left hand column on this site.

Packard was synonymous with the 12s in it's many forms since '15 til WW2. Many design iterations. Lots of mystique and inquiry. When I was at the Packard museum in Warren they had an exhibit on the marine engines. I don't know what the display schedule is now as they rotate.
PT's were made in various configurations as it was kicked off as a competition for design until harmonized. Packard was in the marine market with them to tune of tens of thousands. Maybe a contributor to the market blinder mentality that they had. Success breeds success, to a point...until one solely relies on it and fails to adapt.
I see two 12 cylinder down falls, weight and length. HP / Weight is more important than raw HP. Can't even imagine the prop cavitation in the Miss AM X when one hits the throttle. Larger prop diam gives grip but reduce top end. Must have multi-drives (more weight) One has to connect HP to the medium for movement. One reaches an optimum at some point with the chosen technology - can't get there from here.
We had a similar move in the big block V-8 era. Ultimately coming to a close when fuel consumption peaked and 500 was the number. They knew since the 1870s boosting was the equivalent of cubic inches, but for some reason, maybe political, mostly marketing, it never caught on even with the early Duesenburgs, etc. sporting blowers aka superchargers in the '20s, I recall. Conspiracists say the Std Oil/GM pact at play. Lots of whispers about miracle withheld MPG devices throughout auto history to sell more fuel. We burnt mega gasoline with that faux pas. Now you can go out and make 1000-1200 HP on pump gas with a near stock LS v8. Fits under a low hood too. Go figure? Many 2000 HPs without exotic fuels.
Now "boost" it's the "Holy grail" of "eco" friendly? Go figure?
There's some inherent unpleasant shaft dynamics when you add on more in a longer row. The V-16 was fraught with issues for the same, siamesing 2 8s, lead to quick demise. (try to find parts for those!)
Large multi cylinders like ship and stationary engines go slow rpms as they have massive torque. The Italians, Enzo in particular, went the other way and focused on smaller reciprocating parts/piston diam/stroke and higher rpm to overcome these inherent dynamic constraints.
This was kicked around here at least once before someone asked what the biggest V-12 was or could be. Search the site. Says I've been around too long, repeating myself.
It's reading season for me, so if anyone knows a good book title on P or general V-12 history pass it along. I don't do prewar but this is one historical/engineering area I enjoy.

Surprise email from the chrome shop today, they shipped my chrome order "early" by a few months - almost unheard of? Arriving tomorrow. JIT 4 XMAS! I'll be waxing chrome by christmas lights in the garage...
Merry Christmas to all.

I know the liberty as an aircraft engine but was used in marine for PT/higgins boats, etc.
I worked on one painted wooden boat and I wouldn't own one. It's a maintenance nightmare. You got to keep them wet/swelled or they leak. They look terrific with all sleek styling, chrome & brass trim, etc. but takes a crew to keep it that was. Wood - that's all they had starting off.

They used to run the 12 Merlin's & Allison's in hydro racing. I don't recall many Liberties there. I think they were passe by then. Correct me if you know. I lived on the river starting ~40 years ago and the annual hydro races would be held right outside my apartment and those old Allison's were the unlimited choice, like the miss Bud, etc. They were replaced with the tunnel turbo jets. All these race power plants have roots in the military. War's a hot bed of innovation due to the urgent necessity war creates. Brain thinks faster when bullet fly at it.
The old Cad flat 348 was dualled as Shermin tank powerplant. Interesting stuff military and early evolution of things - at least to me. So if you're trying to "soup up" and old flattie, in my opinion you're going in the wrong direction. Today HP comes easier than from yesterday. The "muscle car era" is really happening now. WE drooled over 400+ HP back in the day, '60s. Now "par" is twice that.

This could be a "gem" see below:
excerpt:
Inventor, entrepreneur, and boat racer Gar Wood set a new water speed record of 74.870 miles per hour (120.492 km/h) in 1920 in a new twin Liberty V-12 powered boat called Miss America. In the following twelve years, Wood built nine more Packard V-12 driven Miss Americas and broke the record five times, raising it to 124.860 miles per hour (200.943 km/h). He also won five straight powerboat Gold Cup races between 1917 and 1921, and the prestigious Harmsworth Trophy nine times between 1920 and 1933, at the helm of his Miss Americas.

Cf: my current 250 HP outboard bass boat runs in the lows 70s, if you like a squirrelly ride. I keep it nice and stable under 70 now - getting old. Two Packard v-12s to get to the same speed range circa 1920, aka boat anchors! ha, HA, HAAA!

Looks like that one flew off and ran down the road from the edge damage. Some of these are notorious for that, so check fit after repair and secure if necessary.
I'd guess it'll be more time and effort than it's worth, but everyone's time is there own. Investing in skills perhaps is justification...
They're not making any new P hubcaps, so preservation is important. I just saw where Toshiba has gone the way of Packard now. Once prominent company now kaputski. There's no guarantee of a company having continued/perpetual success. Too easy to make a fatal blunder. We take that for granted and it's not.
Like everything else, proper tools. Metal working is an art. I use a small specialty trim hammer and anvil that I got from Eastwood for stainless trim. I bought stainless polish and wheels from them too I think. Something smooth to work against is needed, I don't have a shot bag, that might work but could leave dimples if shot too big. Fairly hard sheet plastic, etc. - matching profiles, if possible. A pointy small plastic hammer is OK too. But hard to find. A bossing set is expensive now. I'm debating purchase myself.
Gentle is the keyword. You don't hammer it hard enough to make dents, you tap, tap, working from the edge in usually, aka coaxing out, so you don't get more hammer dings. Metal tends to go back where it came from(memory). Some you can get with one blow in right spot, if you're swavvy. If thin, sometimes you can press out a large dimple with your hands. Have to shrink after if it oilcans - another art. Look at the edge radius of the indentation, gradual or sharp. If it's sharp then harder to work out. You won't get rid of surface damage unless you weld over and grind/sand back. High spots are usually filed, but this is thin to start with so can't tolerate much metal removal. Small very fine files. One can weld stainless with TIG if cracked/damaged but undercutting is common with filler and there's no post body filler here. [Note; it's take incremental sanding to 2000 grit to prepare for wheel polishing.] Cracking happens a lot with thin stainless and can happen when straightening or during damage.
In the hubcap era, we used to pick roadside hubcaps as kids and polish them up as souvenirs, so to speak. If they're not pitted, they can usually be touched up/made presentable, but chrome has to be redone if it's pitted. You can straighten the dents out first and then send off it won't cost as much as letting the chromer do it. There are places that just do hubcaps too. Search around for pricing.
Most of these have an inner steel cage that makes dent removal impossible in places without picks, etc. A good set of picks will set you back $200 or open up the disc and reinstall when done.
Be careful buffing as it's easy to get a haze if not knowing what you're doing much like chrome. And getting them all to match sheen has to be taken into. Tendency is to over polish.

I think as you planned, flushing it more thoroughly, drain well, and new coolant it should be OK til you get it rebuilt. I got all kinds of crud out of the '49 and it ran just fine(cool) when I had it running.
When there's dissimilar metals in a system they are subject to more corrosion. Brass is more "noble" so lasts better in aqueous systems. Cast is better than mild sheet steel.
A periodic extra dose of coolant inhibitor is usually called for with mixed systems but Prestone claims/warrants it's not necessary with their silicate based inhibitors...
Frequent flushing and changing is the best maintenance protocol, usually every ~4 years or so, about 50K miles.
These old systems have more lead based solder in them and heavier gauge brass. The solder is the weak link usually, tends to pinhole/ pitting corrosion.

You might consider having them cleaned and ceramic coated before you return to service. They'll last almost indefinitely that way. Also reduces some of the engine compartment heat as it helps it go outside instead of radiating in the engine compartment. They coat inside and out. Not that expensive either, under $200 / pair locally here(SC?NC) They have a grey cast finish available that's pretty close to normal/rust free. Not for the "purists".

Any 7" round with the right prongs will work/fit. I have a halo set for the '49 but another brand. I think I have some incandescents. Not many choices in this size.
Check your wiring before you just assume it's OK.

There's a section in the 23 series shop manual on how to install the windshield glass. I'd have to go down and look what section # it's in but should be on this site.
I'd say you need a spare set of hands at the minimum. The rope is used to pop the gasket over the edge. When I removed mine I had to remove the trim first, so doubt it would be left on during install as the center pieces screw in through the rubber.

It also is only going to be a partial filter, not gaining much. I wouldn't bother, if you're not driving it much. They got along just fine without them, you adapt. Plus you'll have to clean the sludge from the pan before you install. We're talking motor oil selling for <25 cents/qt in '49, so can't save much money with filter investment on oil changes in the day. Bulk oil was available too. Those antique glass oil bottles were used for that. I packaged and sold bulk in the '70s. Now it's special this or that, and "synthetic" BS. You can get after market full filter cartridge units but may require some surgery at least some plumbing. Full oil filters didn't become standard until well into the late '50s early '60s. Cadillac changed in '61 with an engine redesign. My '58 is partial. You're 10+ years to soon.