Peter Weigle said "Campagnolo made a lot of odd bits, I have a clamp on shift lever that is a single lever,,, left side only, what would you do with that."
Many vintage British frames have right side only shifter braze-on, being intended for use with only a rear derailleur, or in conjunction with a lever front derailleur, for which no left shifter braze-on is needed. If you want to use a cable-operated front derailleur from Campagnolo, Benelux, Simplex, etc., you would need a clamp-on left side shifter to buddy up with your right side shifter braze-on.
Peter
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Peter Brueggeman
La Jolla California United States America
pbrueggeman(AT)ucsd.edu