The Fred Adolph as noted at Baker seems to resemble the true picture of Adolph as a mechanic. He seems to tout his credentials but I'd like to check his references. In the 1920s writers hint to the fact that Fred Adolph has some master engraver/gunsmith holed up at his facility and they considered the subcontracting work to be one in the same as Adolph's. At one time he may have been a whale of a craftsmen, but it seems he was more of a used car salesman and firearms merchant that anything else. I would say that I view Adolph much like Axel E. holds H.A. Lindner in regard; more of a sourcing agent and firearms merchant than anything else.
Let's throw Singer of LA into the mix also.
Kind Regards,
Raimey
rse