I'll be the one to split hairs on this...
Don is correct that 312 and 319 are original San Juan Coaches.
The San Juan interiors of these cars were taken out in the 1957 rebuild and bus seats were installed.
The D&RGW in their infinite wisdom took these cars and stripped the wood exteriors off and created steel exteriors to look like wood. This was done in the late 1970's.
The D&S has been making their own trucks for a while, can't say what the 312, 319 are riding on are original.
I would guess that the interior wood paneling might still be original, but after the 1970's rebuild it might not be.
It's hard to say if anything is still original on those cars. Also 323, 327, the Alamosa and 126 got the same "Treatment" during the late 1970's
It the George Washington's axe paradigm
Kevin Cook