Way to Tell Variant of Labelless Combat Cart?

Hey, all.  I have a Combat cartridge in my collection (forget where it came from) that completely lost its label.
When recently cataloging my cartridge collection, listed by label variant of course, I realized I didn't know where to catalog this particular cart.

I figure this Combat cart could be an Atari Text label, Atari Color Font label, or a Sears Tele-Games label...
A quick look at the physical characteristics of the cartridges gave me no clue (Sears, early Atari, mid-age Atari looked the same).
Any differences on-screen when playing the game?  Physically opening the cart?

So, only out of curiosity, is there a way to tell the difference between these labal-variant carts without the label?

Thanks.