No way were they microfiched in the '60s. There was a gov grant in the early 80s for counties to put their records onto microfiche cards (not the roll which is microfilm). I know this because that was part of my job. If there was a mistake in the numbering, the person photographing the pages should have caught it because the numbers wouldn't have come out even/correct. If the person photographing the file made a mistake they either had to redo the entire thing meaning redoing many, many files or they would have put a note of explaination on the screen. Yes, to err is human but it's difficult not to notice a mistake with this. It's like page numbers in a book with the odd numbers on the righthand page and even numbers on the lefthand page. You know something is wrong when the evens and odds suddenly switch sides.