Norton AMC Gearbox Inspection Cover Washer : 1957 Onwards Type

This is the gasket that fits over the small circular inspection covers fitted to the AMC style gearbox's that were introduced on all Norton models from 1957 onwards.

The AMC style gearbox replaced the 'laydown' Norton type gearbox in the 1957 model year and then continued with singles and twin cylinder models into the 1960's.  I am assuming this gasket will fit all those models (as well as AMC gearbox's).

Made in nice quality black oil resistent material by a specialist UK based gasket manufacturer.

Note - I did also decide to trial fit this gasket on the inspection cover of a late (AMC?) type magnesium racing DOHC Manx Norton gearbox shell I have - see last photo.  This is a nice quality (Summerfield?) racing gearbox - but the inspection cover for that type of cover looks different to this one and the gasket was not a good fit