First time Primus had a transitional model? "A" and "K" only? This has the feet like later early models, early "A"'s have bun feet. The transitional "K"'s changed over from the small, separate air screw to a air screw on the fuel cap. Duane
Having had this thread revised, I note that the stamp on the tin, “REGD 580733” is most likely signifying a Registered Design number. Cheers Tony