Magneto advance retard cable

[Greenfield]

Can anyone suggest what the thread is where the advance retard cable screws into the magneto body (Lucas M01)? At first glance its about 7/16" diam and 26tpi. BSCy ? Its not the cable thread that's stripped, that would be an easy fix, but the female thread in the magneto body!!!

[militaryron]

It's simple to change that end part on an MO1. Is an MO1 the same size as the original type for a B21? I assume it would have had the pre war ring cam type? Just wondering if that might be your carb fitting problem?

[V500]

That threadform sounds right. Can't you borrow/buy a BSCy tap, clean up the thread and Loctite the fitting in?