That's weird, Ed. MKT 13501-13525 show up in Jim Eager's list of GSC flat cars (Railmodel Journal 12/1992).
Tim O'Connor
Tim and Tom, Sorry, my data on the M-K-T 1952-built cars was in error. Thanks for bringing this to my attention. I counted the stake pockets on the 1954-built cars and there are 15. Regards, Ed Hawkins