I know now that the headlamp DU42 is wartime issue. I also have a NOS headlamp MU42. Is this a postwar lamp??
Anybody out here who can give me some information about the MU42.
as far as I know you're correct:
The MU42 was used approx 1947 to pre 1960. Most makes during this period: Triumph, BSA, AJS, Ariel, Douglas, Norton, Panther, Matchless, Velocette, Royal Enfield
The post war MU42 usually has a bottom clip with a hook for locating in the hole in the rim. You use two fingers like drawing a bow. The DU42 has a flat curved clip.
I was told the MU42 came in late 1945 onwards, my 16H had one fitted when I bought it and it's definitely WD issue with the original paint and the "T" shaped clip is dull chromed. I've now changed it to a DU42 to fit the year of the bike.