(consults LV Freight Car Guide) Yes, the brown cars date from the mid-60s and the green cars (USRE rebuilds) were rebuilt from 1969 to 1973.
IM has a 10'6" body style appropriate for the Bethlehem Steel cars, and the MT PS-1 will work with some ladder changes. I'm not aware of a true 7-foot door, but the MT 8-foot version should work. Rich Yourstone indicated that it sizes out somewhere between 7 and 8 feet wide.
So many projects, so little time!
Frank