F is the 6th month, June. All years starting in April of '58 started with an Alpha character at the front to represent the month. A = January, B= February, etc.
A,B,C,D,E,F,G,H,J, K, L, M - no I
1 2 3 4 5 6 7 8 9 10 11 12
But according to the following, which I copied and pasted from the Angelfire website, my theory is KAPUT! The number following the letter represents the year.
NEW NUMBERING SYSTEM:
AS OF ( 04/17/58 )
THE FIRST LETTER IS THE MONTH, - FIRST NUMBER IS THE YEAR.
THE LETTER " I " IS SKIPPED TO AVOID CONFUSION WITH THE NUMBER 1
Examples:
E836708 ---- E = May ---- 8 = 1958.
A = January, ---- M = December, Etc.
9 = 1959, - 0 = 1960, - 1 = 1961 Etc.
F9 would be a June 1959 date.
So my theory is wrong. Hopefully everyone will read this and ignore my post.
Back to scratching my head.