I like the idea of the 1 ton truck posted above.
...BUT... the trailer goals NEED to change significantly. A truck like the OP has in mind needs a much smaller period correct three horse.
This is all make believe anyways, but the trailer originally posted has no chance with anything in front of it like posted. The modifications needed to make the vintage truck match that trailer put the character in the position of being a car guy rather than a horse guy. Unlikely to be talented enough to pull off both successfully enough to be story worthy.
That trailer and truck are at too opposite ends of the spectrum, I think bring the truck up and trailer back are a reasonable approach. Like a late 70's crew cab dually, big 454 engine with a similar vintage trailer.
