Mount Vernon Shops has released HO scale decals for the PRR F33 flat car. From the MVS' web site:
This set was produced to introduce a more comprehensive set for these classes, which hadn't been done by previous manufacturers.
The F33 flatcar was a pioneering car for the Pennsylvania Railroad. It was an entirely welded car, constructed by an outside company, but to the design of the PRR. The roster only totaled 16 cars, but in the service they were designed, shipping medium to large transformers, they were seen across the national rail network. Due to the service they were in, the entire car fleet lasted into early Conrail.
These cars were built in two orders, the first being completed in late 1938, and the other in early 1942. They had a load limit of 250,000 pounds, however the light weight differed between the two orders of cars because of a slight design change in the Buckeye-type trucks. So, the initial 6 cars built in 1938, the light weight was 97600 pounds, but the later 10 additional cars built in 1942, the light weight was 98200 pounds.
This sheet has enough data to do 2 cars, with 2 ready-to-apply numbers, and then additional options for doing your own number. There are six different reweigh/repack dates covering locations where these cars frequented.
The F33 has been done as a resin kit by F&C. Also, the F33 was imported by Railworks, Ltd. in brass. For painting this flatcar in this scheme, the entire car including underbody is to be painted in Freight Car Color. The trucks are painted black.
For references in regard to the PRR's F33 Class Flatcar fleet please consult the Pennsylvania Railroad Technical & Historical Society's publication, Pennsylvania Railroad Flat Cars, Revenue & Work Equipment, 1881-1968, by Al Buchan and Elden Gatwood and Volumes 1-3 of the PRR Color Guide.