Peterbuiltdude, This is the Atlas 62' flat car I bought.
I believe it's an Atlas Trainman 2001711. You remove 4 small Phillips screws (2 each end) from the underneath the bulkheads to remove them.
The Atlas 89'4" flat car would probably be a more accurate choice.
They retail for $114.95 and I don't think they have been released yet.
My plan was to do what Keith did with his.
Larry