August 1971 frame grey (look great in silverfrost)gear lever on right these have the round like engine casings, 1974 square casing no black writing on engine casing gear lever on left with grey frame 1975 Black frame engine has black background to writing writing on casing, casing alloy colour. 1975 Alf Karlson repilica model is same in the 247 till 1977 then 1978 has a different slim line tank and different front mudguard bracket like the 348 & 349's 1975 first proto type 348 in 247 frame and few changes, 1976 348 in 348 frame. 1979/80 mk1 black frame red tank 349, 1981 mk2 red frame white tank red background on engine casing for writing black engine, 1982 mk3 red tank/frame alloy barrels black cranckcase1984/85 MH349 red tank red frame red guards. Note 247 could have gear lever on either side early models as this was an option when requested. I personally preferred the right side gear change for some reason possibly because I am right handed/footed.