if it has the hinged arms at the sides, Fulton-style, it is after market. The factory visor curves and screws to the drip rails

the PAC site has the color charts. I think there was a fairly wretched pea soup green, rarely seen

we can I hope agree on this much- "leatherette" really just means imitation leather. The one you describe I believe goes back to the 1920's or earlier as a way to coat fabric. It could be a good top insert material. While PVC goes back to the 1800's, the plasticized (soft) type became available in the 1920's - 1930's. Sheet vinyl was in use by post WWII (and on the Junior doora)and the commercially prevalent way to offer imitation leather. That said, few if any car companies were using any synthetic leatherette for seats at that time.

I do think it's odd that Packard went from light over dark 2 tones (more visually lowering) in 1941 to the dark over light. I believe the 22nd series factory 2 tones were green, brown, or blue tops on Egyptian Sand bottoms. Plus a 2 tone with greens that sounds interesting but I've never seen.

vinyl was not a later development (it was around before WWII) and "leatherette" is marketing speak for vinyl. BUT for 22nd series convertibles I agree the seat choices were leather or leather and bedford cord (a rather bumpier version than the prewar closed car option). The wiped grain trim on the lower door panels of 22nd juniors is vinyl. Was the leather and cord an option only on Customs or on Super 8's also?

It's your car, but I would think several times about the white top and seats - it's pretty obviously non-authentic. Do it if you like it enough to accept the impact on resale.

The difference between a VAT and US "sales tax" is not so big.

I think the market dictated in the 30's that "juniors morphed into seniors". The surviving US luxury makers (Packard, Cadillac, Lincoln, Imperial) all evolved into cars that were based on more "standard" corporate technology. Pierce Arrow didn't fare so well with the only luxury approach - there wasn't enough market left. I think you can make the case that Buick was actually making the best GM luxury car just before the war, and GM put a halt to that (except there's that nagging babbit thing - please, PeteH, don't say it again).

That said, I agree that the styling carried the family resemblance too far between juniors and seniors. An average old car person has difficulty telling models apart. Don't exempt the bathtubs - a 23rd series Super Deluxe looks a lot like a Custom. Any car maker with a "face" featuring a verticle grille had a styling challenge in the 40's - 50's as cars tried to look wider and lower. LaSalle's issue became moot. Alfa and Packard tried to make the grille smaller and narrower. Rolls Royce and Jaguar just went retro - it's handsome today but very dated in its era.

The bathtub (and Hudson, Lincoln, Merc) had a more streamlined and advanced style that the later GM designs (still have rear fenders). The compromise in those cars is using the narrower Clipper center section. Compare to a Hudson that was done "all at once."

The effort in 51 to incorporate the yoke shape as the top of a contempporary grille shape is a clever try - in my opinion the problem is that the overall shape is so much like other cars of the time.

22nd series junior - painted cardboard type. Believe original

my point is that "bonds with plastic " is way too broad and vague a claim. All paints bond with their substrate if they work. The issue to beware of is that the old wheel's plastic is usually degraded to some extent. If severely degraded, you can effect adhesion. The Krylon is formulated to bond better to some relatively cheap thermoplastics - your wheel is a different type of plastic and thermoset. Now it still may work, but I'm still inclined to epoxy primer or polyurethane.

"plastic" is like "metal"
lots of differences within the category.
the krylon plastic paint is a more flexible paint and bonds better to things like polypropylene and polyethylene, which are hard to stick to (low surface energy). I've used epoxy paint on a steering wheel successfully. I agree that the original was probably enamel.