The decals are a mix. The dimensional data came from Microscale's 87-734 set for CB&Q wood box cars. The other lettering, including reporting marks, capacity, build data, etc., were scrounged from Speedwitch CB&Q lettering. Interestingly, the plate on the door for the "Burlington Route" emblem was too small compared to the decals from Speedwitch, Westerfield, and Microscale. I had to make the white border slightly smaller to fit and it is evident if one looks closely, as the lines are close the the "B" and "n" in "Burlington."
The 500 members of the XM-29 class were built in 1936 in company shops and assigned to nos. 25500-25999. They continued the Q's preference for single sheathed cars. HO scale Q modelers are fortunate as all of the single sheathed classes from XM-21 through XM-31 (the class XM-24 class was 40-ton USRA double sheathed cars) have been available as resin kits. The USRA cars have been produced in both styrene (Rapido, Accurail, and Ertl) and resin (Westerfield and Funaro & Camerlengo.)