Purely a guess, but it would seem that the D&RGW saved the useable siding that was removed from cars during the 1920's rebuilds and reused it where it would not be seen or be on the outsides of cars. Along with 0577 and 280, I have seen old siding reused as the roof boards in several 3000 series boxcars.
The Rio Grande was very good at not letting useable wood go to waste, I have two needle beams from 3000 series boxcars that were made from the side sills of gondolas (both still have partial car numbers on them)
The siding removed from the ends of the 5000 series stock cars could well be the source of the wood behind the stoves on 0577 and coach 280. For what it is worth, the reused wood in 280 is the same color red and has the same style of lettering as the wood seen in 0577.
Jason Midyette
Edited 1 time(s). Last edit at 10/21/2016 07:54AM by Jason Midyette.