I think there’s a fundamental point we need to keep in mind with American Beauty backed T206s. It’s the obvious one: they are significantly narrower than all other T206 cards. And that must have distinguished the way they were printed.
Think of it this way. Two horizontally adjacent cards on a sheet normally had a quarter inch of white space between them (you can measure this on any severely off-center card that shows parts of two fronts), which when cut down the middle created the side borders for two cards.
So a normal (i.e. non-American Beauty) sheet was laid out something like this (the red lines show where the cuts would be made):
An American Beauty sheet would have looked like this (i.e. scrunched together):
Now, one could argue that ALC used the first pictured layout and made extra cuts to trim the cards down the proper size and scrapped the little slits of paper that were left (shown in red), like this:
I wondered about this for a long time, until I saw the Malarkey card below. I know it’s a small image, but you can clearly see, especially if you look at the wavy brackets, that there’s no extra space between the two designs, meaning that only one cut was made to get the card to the right size. So they must have used a layout like sample sheet 2. Which means they used different printing plates to print American Beauty cards.
The similarity in green inks between American Beauty and Sovereign may indicate they were printed concurrently or close in time, but they must have been printed from different plates. And to me that makes connecting American Beauty to any other brand tricky. Not impossible, but tricky.