When I hear 1955
, I think vintage tow vehicle.
But, when I think vintage, I do not think good mpg.
Retro-new comes to mind, but they all seem to have tow capacities of 1K. Maybe the Jeep Wrangler 4 door is worth a look as it should be the exception.
CanAm modified a late model Corvette to tow a 23. There was a picture of it on their web site. That is interesting, but even more so if you could afford one of the C5s, that was built to look like a C1. A very cool tow vehicle indeed!
You could also talk to CanAm about a 2001-2004 S-type jag, which looks vintage. It's comfortable, gets reasonable mpg, and they sell cheap, because Jags can be expensive to repair. Find one that has seen proper care. Not for all, but maybe?
Some day there will be folks who build interesting Resto-mods that are configured as tow vehicles. Factory Five has a 32 kit car that would be quite interesting if it was powered by a late model gas or diesel dual stage turbo and multiple speed transmission.
Otherwise, see the posts above. The Chrysler sounds very interesting and the Flex seems like a perfect TV for a smaller trailer. Too bad an HHR wouldn't work.
Then again, you could forget about that mpg and find a nice Red Caddy.
Good luck, vintage has got to be fun. Pat