This Clutch Nipple sits on the pin on your clutch pressure flange. This slightly redesigned, and hardened nipple is made for MB Scooters.
The Complete Spanner's Manual: Lambretta Scooters by Martin 'Sticky' Round Third Edition 8100072
The Complete Spanner's Lambretta Kit Book 8100027T
Eibar Lambrettas 1954-1989 by Jaime de Prat Salomone
Lambretta and Vespa Street Racers BOOKAZINE by Stuart Owen