Here in the UK, at least 3 railways have been re-creating Victorian 4-wheel passenger trains, due to a lucky accident of history when many railway companies sold the bodies of such cars for use as cheap housing after World War 1. Now, after nearly a century, some of these cars have been retrieved from inside houses, gas stations and farmyards among other places and restored to their original use on replacement chassis.
One thing that has often happened is that many of these cars have become hybrids - in the sense that they now contain parts from more than one car. If a car body is found which is too far gone to be restored in its own right, it is dismantled and any parts/timbers which are still usable are recovered for use in other, similar cars. A frequent source of replacement chassis has been 1920's-30's Southern Railway PMV's (Parcel and Municipal Vans), which are dismantled (sometimes with re-usable timbers, such as curved roof beam, recovered for use in passenger cars), then the chassis is shortened, the running gear and brake equipment re-located and then the car body is mounted on top of it. Some of the results are shown in these pages on the Bluebell Railway's website:
LBSCR 3rd #992
LBSCR 3rd #992
LBSCR 1st #661 (which I have ridden in)
LBSCR 1st #661
LCDR Brake 3rd #114
LCDR Brake 3rd #114
LCDR 3rd #3188
LCDR 3rd #3188
The Foxfield Railway, a former coal mine line in Staffordshire, now has a rake of 3 North Staffordshire Railway 4-wheel passenger cars, restored from derelict bodies, and mounted on adapted 4-wheel freight car chassis:
The Isle of Wight Steam Railway has a mixed set of restored 4-wheel passenger cars, restored in the same way as those on the Bluebell Railway:
Isle of Wight Steam Railway 4-wheel coaches
Does similar restoration work, involving restoring cars with suitable salvaged parts from other cars, take place in the USA?