Jerry,
Back in the day the B17 Champion was slightly narrower (ca 145 mm) than the Standard. Other features included a frame that was lower at the back where the rails meet the cantel plate by about 1-2 cm, no bag loops and champhered flaps, and black steel rails. The Standard was wider (ca. 180 mm), had bag loops, the steel rails were much higher and the side flaps were not champhered.
Michael Allison
New York, NY