Micke,
You quote the wrong numbers E3 M3 is for the dynamo part: E = eccentrically mounted, M = dynamo for use on top of a magneto (magdyno). The AC marking means anti clock. The base of the magneto should hold the key. I expect it to be a type MSL1 with a mont and year dating like 232 (February 1932).
Regards,
Leon
http://home.planet.nl/~leonhop3/home_eng.html
