Guys:
I think that Bob Sloan in his new book on D&RG(W) freight cars has a supossedly complete list of all the Rio Grand tank cars and their dispositions. I am at the Miami Library now so do not have the book with me but I will look when I get home and post later. It seems to me that all the frameless cars had the cast trucks and that all of them went to first the 34 ft stock cars and then in the 1950's to the class 6500 flat cars and now reside under the CATS passenger cars. Will get back to you later when I look that up.