I'd like to see the "science" and algorithm behind those curves.
Specific HP vs speed? I musta missed class that day.
Let me see, if I put alot of lead in my trunk and go faster, my valves will recess more? Got it. Cement trucks don't stand a chance.
The only thing that goes past the valves/seats is atomized fuel or exhaust "gases". They only contact for wear when closed and only on a very small surface area. So explain how a fuel additive, which was used as an octane booster, is going to matter for that?
The metallurgy was changed and that was more impactful. Of course, we still hear about the "explosions" that go on in the cylinders on TV.
Got a few bridges I need to unload...
We believe what we want to believe and that's final.

http://kaufmanauctionswv.com/index.php?srch=1&srch_term=lifetime%20cars&mcid=13&type=all&view=auction&utm_source=ClassicCars.com+Newsletter&utm_campaign=7eff0fb584-061520166_15_2016&utm_medium=email&utm_term=0_59461abf0d-7eff0fb584-162236125

This looks like a very big collection. I just got the info and haven't had time to digest.

drivers range from about $8K to $23-26k for a pristine original survivor based on sales/asking info. Mid teens is about the asking median I've seen. So if it's solid/all there, not running, $8-12K asking is not unrealistic depending on condition, but if you look around you might find a much better one, running, for nearly the same money.
If it's not running, I have a std way of handling that, but the old guy probably won't go there. It's always an emotional deal when the owner is elderly and a long time owner. If you don't know these cars, take someone with you that does. You can get into significant money, for a car that won't bring that much more after it's spent. Just for info, I've got $6K just in chrome plating for my '49 and that does not include the bumpers. Motor rebuild ~$4k, but I don't spend money for a 100 HP flat head. Can't get gas tanks for these. Interior materials are hard to find.
Something this old will have electrical and/or drive train issues. And sitting; fuel, brake, and cooling system problems. They actually need to sell for negative money to make out.
You can find most of the info you need to authenticate / identify the vehicle on this site if you do it yourself.
These post war cars aren't that desirable stock or they'd bring alot more money. I happen to like the fastback design.

O_D -> Disagree all you want, no need to polarize your alternator!...
Handwriting was on the wall, even if the load didn't change the world would have got away from 6V + grd. The + grds seemed to leak off faster. I can't recall how many times, nearly every, I had to charge up the old 8N before I could cut grass. Battery life just wasn't good. 6V - good for flashlights not cars. There's a 12V gen and reg on the Cad. Weighs a ton but no complaints. Packard 6V worked OK.
I had a hypothesis that the pos grnd actually made the car less susceptible to corrosion (via anodic protection) and the switch to neg possibly accelerated it (cathodic - car becomes the anode). They came a long way with corrosion protection since the early 12V days of rocker panel and headlight bucket replacement.

If you use aluminum heads on a cast motor you have to use special anticorrosion additives in the cooling system and gaskets. This is very common in today's motors but sure was not well understood, if at all, in the day.
It took alot of engineering work in sealing, bolting, and corrosion to introduce aluminum motors/radiators.
So on a 800+ lb motor does saving ~50 lbs(guess) on the head weight without increasing HP, really warrant its use?
Paint it silver!
Maybe just one more thing leading to the P 50's demise...You can't have alot of screw ups and survive.

as small as those cracks are, just call them survivor "patina" and ask more money for it...
I still think they could be fixed easily as outlined before. If it's cleaned/prepared properly, the epoxy will bound to the butyrate. Color matching is not so difficult since now the dark is what is showing up(contrast). If lightened up to equal tone but not exactly the same color, it'll be less distinguishable. Buff out and the shine will also cover it.
Of course you have to have a pigment supply. If you want 100% match -> air brush.
ps: alternates.
What I did on my Caddy, was buy one of those sew-on leather wraps to cover the whole unsightly steering wheel that was improperly repaired. They cost about $80. I got mine from "Wheelskins". Takes about an hour or so to install. Looks great in two tone, matches interior. May not cover that area but one option, some sort of wheel cover.

If it was "1" crack you might have a chance with TIG, but soon as you say "CRACKS", it's probably fatigued/corroded beyond service life. Would have to clean and use die penetrant test on it, first, to see where and how bad it is. If localized, maybe able to machine bad parts of it out and make/weld new machine patches, but $$.
Just another sad fact of flat heads due to the stress distribution even though they're somewhat low compression. Same applies for cast iron ones. Nature doesn't like flat, it tries to bend it under load, so that cyclic bending stress adds up over time leading to cracks. Al thermally expands a bit more also than the cast so when you try to hold it down on tight to cast, you're adding to it. That was one of the crowning achievements of the "hemi" head. Mimics the natural shape.

If it's not too late, make sure you use rosin core solder not acid.

My '49 wheel is brown but the under plastic is very dark brown or black. The common method is using PC-7 epoxy putty to fill the cracks, then you sand them and paint. I started but never finished mine yet...
Looking at those cracks, they're dark inside. So either they have accumulated dirt or the under material is dark.
If I had this problem,
1. I'd take a dental pick and clean out the grooves down to clean material.
2. Clean with rubbing alcohol and dry. Alcohol will also cut epoxy for clean up but don't thin with it. It won't cure right.
3. Fill with a matching color epoxy. I'd use slow cure and tint. It's about the same shade starting off. May not even show. Even fingernail polish in the right shade would work, but you have to apply several coats to fill the space. There might be some epoxy sticks or tint kits for fixing plastics or wood that might also work.
4. Sand and buff out.

As plastic ages it shrinks due to continued polymerization and loss of volatiles/break down products. The material in the crack surface can oxidize so it won't "grow" or heal back with solvent, you have to fill it. That's why you want to dig it out first, to get a good "tooth".

Might want to cal them directly.
They sell through some distributors that might have stock, if they made any.