As I understand via Chas (RIP), the Campy NR sidepulls were added to the Gitane Super Corsas once in USA though my SC shows no sign of ever having the standard Mafac centerpull mounted, the paint on the hanger is unmarred. The frame-attached hangers were dropped from both the SCs and TdFs in like 1971. Your crusty with the swagged and crushed seat stay finish most likely never had a hanger.