That rear hub has to go! NC30 sprocket carriers are interchangeable with the RC30 (which had a black version, rather than the gold one on the NC35), but of course, you'll need an axle, and a centre-nut wheel....
I'm not building a replica of anything, but I enjoy showing people how little discernible progress I make on my own bike projects. Here's a pic from 2016:
(It still looks like that.)
The swing arm on my bike is from an RC30, which are not easy to find, unfortunately. An NC30 swing arm might fit, but it's probably quite a bit shorter than the OEM arm (I don't have the measurements to hand). However, it would solve a lot of problems. Good luck.
Ciao,