There really aren't any
The German FG42 was the first true assault rifle.
$150-$270 for Good or Excellent condition. New in Box is $385
100-500 USD
A mile or so
500 or so
250 USD or so
about 120
I would use a 22 long caliber rifle, a Kember,Browning for the pistol I would use a 9mm or 22 long rifle pistol a Kimber, or Sig Sauer.
The Marlin 9mm Camp Carbine will accepts the S&W Mod 59 Magazine . Joe-R
Tech 9, 9mm rifle and a couple shotguns.
Best left to a gunsmith
only if you have installed the aftermarket heavy-duty recoil spring (Wolff springs) and the buffer is in good shape.