For your information,
I have Schwinn Paramount P-15, original N.R. Campy chieen rings 54-49-36T, 144 BCD. Serial number H-72259 (Aug. 1972), with N.R Campy front derailluer, slick face (means, there is no round pivot scoket at front), production from 1964 to 1972, but no outer cable stop type.
This front derailluer (mech) later had "bent" tip after CPFC law change in 1976, then had 4 hole to 3 hole cut outs (became part of Sup Record Group) and lasted well into mid 80's.
I suppose basic design never changed to over 20 yeatrs?
Best regards,
KEN TODA, High Point, NC, we are here in Spring wreather 70's!