Hello Sirbrider and paul_c

Thanks for those links Paul!
This should be easy to advise on - but only with more information.

The Scott Bonnar electrics were made since 1923.
By the 1950s the electrics included both mains and battery electrics.
They did not have an engine clutch as such, but only a landroll clutch.
The primary clutch was the on/off switch.

So ... we need to identify the specific model.
I'm not sure what cork has been replaced.
If its a 45 it will be in the chaincase; if a Model 40 it will be
inboard, next to the roller.

Serbrider, we need some photos:
Information on posting photos may be found HERE.

Hope this helps.
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JACK