Hi Micah,
Musical Instrument City of Rangeley, Maine periodically has some interesting older stuff.
Some years back I picked up a Besson 4v non compensator from him.
Horn is circa 1903-1908 marketed in the US by Carl Fischer.
It may have been HP converted to LP.
They periodically list vintage stuff on E-Bay. Also, Google can still find them.
Good Luck with your search.
Jim
Jim Babbitt
1960s 4 valve and 1971 3 valve Besson New Standards (Denis Wick 6BM) for regular playing
1936 Conn 5 valve 30I Double Bell (Bach 6-1/2AL) General Purpose Back -Up
1924 Buescher 5 valve (the Denis Wick is close) and 1940 Holton 5 valve (Bach 6-1/2AL) Double Bells for kicks.
1860s OTS Saxhorn when history is required (the Denis Wick fits)