Thank you Bernie, I have obtained a lock plate but it sits proud of the fly wheel as the crank is not recessed. I might need to cut a bearing size hole in the middle. Your phot was helpful as it specifies torquing it to 36 lb which is almost double that in my 1938 to 1950 12/15 repair manual. It is possible with these later tractions that it was set to 36 lb.
Alain Sauvage