I think my 25-35 Highwall short rifle, (serial 104783, 15″ round #3, made in 1907), was the very first exempted by the BATF.  I am an old and long past member, and the rifle is in my old “Cowboy and Gunfighter Collection” in the Craig, Colorado, museum.  My last specific info was in the Spring 2000 Winchester Collector, and there were nine 15′ M1885s with short barrels listed.  I have sort of presumed that the other eight were low walls.  Can anyone give me more specifics or newer info?