You are correct sir, the 3-cell did not see any use within the MTO/ETO. Also, the M3 (which came first) DID have the cocking handle. The M3A1 (the improved model) had the cocking handle removed as it proved to be a weak point in the M3’s initial design.
the Thompson used to be his baby back when you could get the bfong blanks easier and before he hurt his shoulder. Now its a really expensive decoration for his jeep.