Date question on 2 a/c boxes

Hey members, I have 2 boxes (looks like the 2 piece 67-72 a/c, boxes) and the dates seem to be 10/7/65 and 5/15/66. I bought a A/C parts lot from a local guy who bought them not knowing what they were either. I'm using the 10,000 day calendar but must be doing something wrong, makes no sense to me. Thanks, dates read 1532A and 1752B.

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