First initial of serial number is the Month. A=Jan B=Feb C=Mar D=Apr E=May F=June G=July H=Aug J=Sept K=Oct L=Nov M=Dec
Second initial of serial number is the Year. 3=1963, 4=1964, A=1965, B=1966, C=1967, D=1968, E=1969, F=1970, G=1971,
H=1972, J=1973, K=1974, L=1975
Krates with the stick...