[Kevvyg1026]

For the checklists in 1965, this is what I observed:

In series 1, col 2 had check 2, Col 11 had both checklist 1s.
In series 2, col 2 had check 2, col 11 had check 3
In series 3, col 2 had check 4, col 11 had check 3
In series 4, col 2 had check 4, col 11 had check 5
In series 5, col 2 had check 6, col 11 had check 5,
In series 7, col 2 had no check, col 11 had check 7

So, it appeared to me that when a checklist was repeated in the following series, it was placed in the same column as it had been in the prior series. In other words, the even-numbered checklists appeared in column 2, irrespective of which printing, while the odd-numbered checklists appeared in column 11. That is why I expect that in the Series 6 printing, col 2 will have check 6, since check 6 was in col 2 during the 5th series printing and is an even number while check 7 should be in col 11 since it is in col 11 for the 7th series printing and is an odd number.

The check 6 variation in series 6 should be the one with the "full m" shown on the back near card 481.