Yes Mitch, the early box had a different casting to retain a rubber Jonnie. Ron

email (option): ronpier@talk21.com

Thanks Ron

I see from the multitude of pics that these are mixed, due to years of work on the bikes I guess.
Any idea when the transition from round to rectangular happened?

I am matching boxes to Several project bikes, hence my interest in getting a better suited match.
1937 M23 Empire Star
1940 M23 Silver Star
1942 WM 20
1944 WM 20

My restored civilian 1945 XM20 has the round lug.

Tsk Mitch

email (option): Mitchm@ppetech.co.a