Raimey, I think there were ads for single barrel traps during the earliest of the Folsom era. I am not sure where same might have been assembled, but some workmen did move to Norwich in the change over period. The reason I am guessing on the assembly of the traps in other than Batavia is that I see the latest traps in the Baker serial no. range and there seems to be no loss in quality, unlike the doubles.

http://www.bakercollectors.com/