Ill take that bet Ted.
Let me share some more data which is till, just theoretical but please check it out and consider it as I have with your 12 sheet theory. I can not explain every situation but a good majority of the 460 series breaks down into 34 possible groupings.
I can also show why certain cards are excluded form certain backs. You need to see it holistically. Lenox is simple,
Here is BL460.
Here is P460F25 in two prints, the second run I believe swapped out Ames for Dougherty (just my theory based on looking across all 460 brands).
Each 28 group can combine with the 6 subgroup as well as the 21 subgroup combined with the 13 subgroup = 34
