Destry, here's a shot showing more of the stock; maybe it'll help confirm/eliminate this as your "mystery" stock. These guns are another of the many built on John Browning's patent; the earlier Savage models had the hump back; guess they tried to modernize the look with this profile. If the Rem 11 is the poor man's A5, then these are the even poorer man's Model 11. It's the only gun I ever knew my father to own; dates from the early 50's. I know they were made in 12 and 16; I've never seen a 20 but I guess they could be out there. The "a" denotes a lightweight alloy frame.