Dr. Bob, A.P.Curtis was the Ithaca plant manager for the midteen years and did redesign the single barrel trap bolting. I don't think he had much to do with the double as the top bolting was a carry over from the Minier days. The try gun illustrated in the L.C. Smith book is also a Curtis design. The Curtis Flues SBT also had a wrist adjustment for cast as I recall. I once owned one.
We can talk more in April.

Walter c. Snyder