"Ithaca seems to have dominated the classic single barrel trap gun market!?!"
No argument regarding the market domination, not necessarily the trophies

Shooters using LC Smith guns won the Grand American Handicap in 02', 06', 11', 19', 20', 27', 28', 33', and 35'. G.W. Lorimer and W.E. Gordon took 1st and 2nd at the 1919 GAH. Using a Smith SBT, A.J. Stauber set the world's record in 1931 with 1087 straight clay targets. He also held the high average on A.T.A. 16-yard targets in 1926, 1927, 1928, and 1932. The first five high average shooters in the ATA in 1933 all used Smith guns. Walter Beaver won the 1933 Grand American and the 1934 and 1946 North American Clay Target Championships with a Specialty SBT. Jordan Royall, using a Smith SBT, and Sam Vance with a DBT, were 1st and 2nd in the 1935 GAH.