It can't be mate I bought it early 70's.
Tony.
You must be a time traveller then mate or your memory is playing tricks with you.
These are BSA Airsporter serial number prefixes 1948 to 1986.
G Airsporter MK I .22 1948 - 1954
GA Airsporter MK I .22 1954 - 1958
GB Airsporter MK I .22 1956 - 1958
GC Airsporter MK I & Transitional to MK II.22 1958 - 1959
GD Airsporter MK II .22 1959 - 1965
GE Airsporter MK II .22 1965 - 1967
GF Airsporter MK II .22 1967 - 1968
GG Airsporter MK III .22 1968 - 1969
GI Airsporter MK IV .22 1969 - 1971
GJ Airsporter MK V .22 1971 - 1974
GK Airsporter MK VI .22 1974 - 1979
GL Airsporter MK VI .22 1979 - 1983
GM Airsporter 'S' MK I .22 1979 -1983
GN Airsporter MK VII .22 1983 - 1986
GP Airsporter 'S' MK II .22 1985 - 1986
GR Airsporter Stutzen + Carbine .22 1985 - 1986