There's a photo on the Wheeler CD of an unusual SOO 50' box car. It appearsSOO series 175000-175498 built 1937 (even numbers only)
An unusual design unfortunately. Many of the 50 foot steel cars were
one-of-a-kind designs. The door opening was 12'6" and the car had a
10'1"IH (perhaps because of an interior rack?).
Red Caboose makes a 40 foot double door car that is good for SOO,
and no one else.