Kurt Laughlin wrote:

Actually there are a number that would work (A-50-12, -14, -15, -17, -18;
B-50-22, -30, -36, -38, -41, -51, -53; and these unknown types:
219206-219805, 606000-606003, 620085-620100) as they are all 50-6 x 9-4 x
10-6, the most common size of 50-footers on the SP at the time. The -38
and -41 were the most common of the common though.

Um, Kurt, there were roof and end differences. It ain't all about interior dimensions, you know. And to go further, the B-50-41, -51 and -53 were plug + corrugated door cars. These are hardly interchangeable with the regular 50-foot double doors. Modeling the -38 vs. the -41 would require a bunch of different modifications.
If you look in the box car book, you can see all these details, as well as the fact that the car numbers listed can be defined (B-50-40: 219206-219805; the 620,000-series were various XAP cars equipped for auto engines, etc.). Not sure why you left out B-50-35, but certainly the -38 cars were the most common of the ones listed.

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