The Marlin Camp 45 is probably more practical.
I have a TM1 semi-auto carbine made when Auto-Ordnance was still owned by Numrich Arms of West Hurley, NY. The TM1 is (obviously) modeled on the M1 Thompson of WWII.
sights and accuracy
The sights have an aperature for 50 to 100 yards with a notch cut in the top of the loop for 200 yards. The notch is offset to the left, but on target for the 200 yard mark. My nonadjustable aperature is about 5 to 6 " to the right at 100 yards. Groups with Walmart White Box Winchester .45 were 8" and with Walmart Federal were 4.5" at 100 yards. At 25 to 50 yards my sister and I were hitting plastic softballs pretty easily.
cocking the gun
The cocking handle accomodates one finger and the recoil springs are heavy, so yes, cocking the Thompson is a problem. I put black dymo labeling tape around the mouth of a spendt .45 case, press fit it in the hollow cocking handle, and sealed it in with enamel, for a two finger extension. Sounds bubba-fied but I have grown to accept it.
weight
The all steel version is 11 pounds, same as the original. It is heavy. A M1 Garand .30-06 will weigh 9.5 to 10 pounds depending on density of wood in the stock. A M1 carbine is 5.5 to 6 pounds. Did I mention the Thompson is heavy? Over 12 lbs with a full 30 shot mag.