The bobbin winder I showed was from 1917 with Scroll(red) decals and was put on the 66 that I believe was from 1908. Have you disengaged the winder from bobbin winding position and then unscrew the adjusting screw and push the winder so there is no space on the right of the screw (yellow circled) and then tighten the screw? I also have other 66s from 1929 and 1949 that have different (from the ones on this thread) bobbin winders with the electric solid hand wheels.
Janey - Neat people never make the exciting discoveries I do.