G'day Lightningpower.
Here's the part #'s to get you started.
A7 1947-50 = 67-24, 1951-53 = 67-380, 1954 on = 67-1061
A7ST 1949 = 67-182, 1950-51 = 56-524, 1952-54 = 67-1063
A10 1950 = 67-250, 1951-53 = 67-1065, 1955 on = 42-0180
Casting #'s are one less than the part #. Small fin up to 53, large fin 54 on.
Cheers