I dont have any new info on Mr. Southgate, but I remember going to his shop as a small boy in the 1950's. My dad had been given a .29 cal. halfstock percussion rifle by one of his friends, and had somehow heard of Mr. Southgate. My uncle was stationed in Nashville, and while we were visiting, my dad made a trip to Mr. Southgate's shop, which was in a building in the middle of a pasture. Mom made him take my brother and I (ages 5 and 6.) We had to stop, open the gate, and close it after us as I recall, because he had cattle in there. One of the things he was doing at the time was rebarrelling the little .310 Martini cadet rifles to .22 LR. He had several in the rack on the wall. He told my dad they made the nicest little squirrel rifles. Dad bought 3 of them from Klein's Sporting Goods in Chicago for $7.10 each when we got back home to NW Indiana. I was probably 6 or so at the time and dont remember anything else about the trip, so I must have been impressed with Mr. Southgate and his shop.
Mike Mullins aka Mikeyfirelock