This resin kit car was released in 1993. Trucks and couplers not included. C&A supposedly also did a double door version of this car, alhough I have never seen one. If you have any pictures of finished cars, do please send them to me!
Built starting in 1937, The B&O "wagontop" boxcar (so named because of its curved top rather than the more traditional mostly flat roof) came in two versions, the M-53 and the M-53A. In 1950 there were 1,935 M-53 (road numbers 380000-381999) and 991 M-53A (road numbers 385000-385999) remaining. The external difference between the two versions is apparently a row of rivets running length-wise between the ribs along the top rounded corners of the cars. The flat doors with which these cars were initially equipped were replaced with the lighter and better functioning Youngstown doors starting in the 1940s through the 1950s.