Hello all-thanks for an informative site! Slightly different topic, tried to load film into my Dad's old Leica IIIa to try it out. After 24 frames I rewound, developed at Walgreens, found out none of the frames had been exposed. Apparently the film leader never was "caught" by the internal winding teeth. Tried again with a new roll before replacing the bottom plate but again the internal teeth gears would not engage into the film holes to advance the film. Did not seem to matter how far in or out the leader was positioned on the receiving spool. Any suggestions or should I just gaze at the camera lovingly? Thanks!