Not much redeeming social value here. The young guns won't know what a straight eight is, nor like it's limitations, and the old guys won't appreciate messing with one. Might as well drop a SBC in it. Lot of expense to replace a one bbl carb????

Painting outdoors, just pick your days when the temperature is right day and night and the humidity (low) isn't going to change much.(i.e. stays above dewpoint) The flashing of lacquer thinner can easily cause blushing, co-condensing moisture on the wet paint, and/or fisheyes from moisture collecting on the surface as you lay down. Choose you're reducer for the conditions.
For a multi layer lacquer job with color sanding in between that maybe difficult outdoors. May take months for good weather especially for the clear. It's much better if you can do in a garage at least. You'll still want the shelter to keep dust and bugs out. I've painted in my garage like that. I painted one outside once and won't do that again. Maybe a friend or body shop may help here. They might let you paint in evening or weekend. Preparation, preparation, preparation...I was at a car show and some guy asked me how they get those paint jobs. It's easy to spot the ones that were prepped.
I like shooting lacquer, but it's getting hard to get, expensive, etc. I'd say an acrylic enamel would give a better result in these conditions. Less reducer, it's easy to shoot, especially metallics, and dries to touch in a couple hours. You can recoat quicker, get better wet gloss, coverage in fewer coats, no clear, and only need to buff out any imperfections.
Urethanes require skin and breathing protection.
The addition of acrylic only enhances the UV stability of the paint.

Gee, I wish I'd known they were that rare. The guy I bought my '49 from, had a '49 limo in decent shape, and wanted to sell it and the other 4 sedans, but I wasn't interested. I remember the limo being light colored/ off white inside, with curtains, etc and black exterior.

I understand. Thank you for your service.
Best to go look at a large supplier with inventory. You might get a better deal on last year's or a demo. Probably a good time of year to be buying one, too.
I doubt you need much extra length, unless you're going to a longer car later, store stuff in the P/U bed. Just big enough for what you tow.
If you go with an open you just have more cleaning to do when you get there and risk damage. Depends how much your time is worth or how good your insurance man is but almost the same as driving it there...just the odometer doesn't move.
ps; my tires were major US brand, new not even rotated yet, when the one blew. Insurance inspector said it was defective - no sign of puncture, side wall just let go. They subsequently redesigned these tires. After many years and much soul searching, I've gone back to them and just bought a second set. They're even heavier now.

You're having to match the rotational speed of the cable to the speedo to give the right reading.
Some have gears to change some won't ever be right.
If it's an electronic model you can program it for wheel size etc. You can have the speedo upgraded to look original but modern electronic guts top match. Just how much you want to do to get an accurate speed. I'd talk to the suppliers and let them figure it out.

If you go on price only, you can cause yourself problems - i.e., how much you value your life and equipment.
A few things to consider:
Total weight of trailer and vehicle, not just length.
Where the center of the load will be. (affects tongue weight - best over the axles. That's what a goose neck does.)
Allowable tongue load and towing capacity of truck and hitch system.
Some states require brakes on all axles, some do not, so you have to think about how to stop it also.

Personally would not pull a "valuable" classic vehicle very far without a diesel dually and enclosed trailer. I'd have it shipped, if I didn't want to invest in tow equipment. Cheaper and less hassle for the occasional haul.
I had a rear tire blow towing with my 4x4 down hill at interstate speed, and it wasn't pretty once the rim went down on the pavement. Thankful not much traffic in that rural area or I wouldn't be posting.

It's viral and there's no known cure for it...
Try liberal quantities of your favorite cold alcoholic beverage to ease the pain. Best to have a well stocked fridge close to the work. Lacquer thinner vapors are also known to make things look better but the combo or the new paint stuff is lethal. You'll end up like myself and others, if you do...

Be careful, if it's got rust blisters, weld won't stick and will burn through bad. I had to cut down to good metal and fab a new neck out of an exhaust adapter. I couldn't find anyone selling NOS or repro and they're weird bolt pattern size and nothing fits. I looked at hundreds of necks to try to find one.
U might try brazing or other low temp repair but no guarantee there either. I guess they could make one on a CNC machine.

Resto Suggestion: If you go to PAC and ask a roster keeper and you don't get an answer, what's a person to do? If no one here has an answer either you're SOL, left to your own research/judgement.
By parallel, I was able to buy an "authenticity manual" used to judge for my CAD from CLC. It's by no means complete but answer alot of the usual questions like this.
A similar document for year class Packards would be a good undertaking and moneymaker for the PAC. They must have some sort of sheet or your at the mercy of the GODs => Good Old Dogs come judgement day. It needs to happen before it's too late. Alot of the expertise is in the -genarian categories.