Lambretta Crankshaft and Layshaft Spacer Shim 25mm ID 1.5mm MRB0619M15

 This is a crank shim to fit between the crank and drive bearing.
It will space the crank away from the drive oil seal plate. 
It can also space up the layshaft if fit between the layshaft and bearing to tighten the main gear shim.

Size 0.8 - 1.5mm  25mm ID 1.5mm

 MB Scooters

You can  replace the drive plate to a MRB one MBP0085 

MRB0619M15