 The new Commissioners engine from 1937 was D3 683, specially fitted with an electric headlight (Mort Clark Bulletin Article) and in August 1950 it was replaced by D3 639.639 herself was withdrawn in July 1956 and replaced with D3 658, however 639's numbers were transferred to 658.D3 639 (658) was replaced by new 40 M.P.H, Clyde EMD diesel-electric Y 123 in January 1964.