Lists and advertisements for official or authorized inspectors of railroad timepieces were regularly published in industry sources. Some listed watchmakers/inspectors were also jewelers. Any available lists or ads could be useful, so please add what you find.
From: RAILROADERS RECORD Seniority-Time Book 1935-1936 covering S.P. Coast Division, W.P. Western Division, & A.T.& S.F. Valley Division.......