Waiting to learn more! I would agree with everything you said so far. But B serial means 1939, I think. FWIW, my gut feeling is that these are much rarer than Paramounts. And I suspect they were brazed by the same few brazers in probably the same jigs. Would that have been someone named Wastyn? Seems like fitting the miters and the actual brazing might have taken a bit more skill than using the very expensive for the time, lug set. Catalog shows Paramount frame at $30, Superior at $20. I think the Paramount tube set might have been more expensive, also. I have a similar condition 1940 in original but chipped burgundy. Tourer model but one ancient brake caliper. Nice find. Chicago history.