My husband was in the AirForce and he made the same observation about the date.
Another thing that smells is citing an "AFM" (AFM 35-13) as authority for an order. I dunno how it's done in the AF but in the Army, whenever it was considered necessary to cite an authority for an order, the citation would be an "AR" - Army Regulation, not an "FM", field manual. Field manuals told you how may steps per minute and how many inches per step were appropriate for Quick Time March, or how many feet to locate the latrine from the kitchen. They did not have legal force. Almost everyone in the Army (who thought about it) understood that AR's derived their authority form the UCMJ which was public law, an Act of Congress. FM's told you how many onions to put in pound of Army chili. Could be wrong, I'd like to see any similar validated documents from the same period and the same unit.