Cylinders, piston, heads, and with that kits are interchangeable between some the honda 2 stroke 50's. PA/NC/NA/NU all use the same bolt pattern and stroke. Exhaust for PA's will work on NC/NA/NU's but other then the Proma Lowboy you'll need to loose the kickstand.
Carbs? not sure; anything with an auto choke can suck a dick though.