Thanks to Norman (teckguy_58) again for yet another US ex-military stove. This is I believe a Coleman 520 which was issued to the US Civil Defense organisation. It is marked "Coleman, US, 1942" although the canister is dated 1944. Norman says that there were shed-loads of these around at the end of WW2 so they were issued to Civil Defensr outfits. Very similar to the M1941 but has a smaller filler cap, a different control knob and is painted olive green instead of army drab. It will be going to my daughter's "2nd US Rangers" re-enactment group where I expect it will be repainted to army colour and be passed off as a M1941 for their exercises. Thanks Norman.