https://www.lakestatesarchive.org/CRIP-Mechanical-Engineer-Files/Freight-Cars-Wooden/i-mbmc5fv/A

For these 1915 vintage cars, you can use Westerfield decals, as shown on their cars here

%WESTERFIELD_MODELS_SECURE _MODEL_STORE% - 6400 40' SS FOWLER BOX CLONE, RI, D&RG, D&RGW, M&StL (securedata.net)

Or

https://www.lakestatesarchive.org/CRIP-Mechanical-Engineer-Files/Freight-Cars-Wooden/i-9c8w6Hv/A

Rocket Express has expressed some interest in doing cars like this second example, these were also later versions of the B2 cars.

Some differences in layout and content.  True, the Westerfield ones might be adaptable to the 1930’s vintage cars.

Jack Mullen