Odd! I've never seen those before, casper.
As well, the normal field load for the 2 3/4" 16 bore ammo today and back in the 60's(my hunting buddy then had a Model 12) was/is 1 ounce. That's what the last Federal high brass I bought were loaded with.
I guess from those boxes, the 2 3/4" back at the turn to the 20th century was 7/8oz.??