It’s pretty easy to parse the loom and get certain circuits back together as the 2 models share some basics. But it might be easier to separate the loom entirely and run all new, simple circuitry based upon it being a “chopper”.
For instance, are you running front and rear indicators? Electric start? Dual gauges? A clutch safety switch? All these things are part of the standard loom, and the lengths, sub harnesses and what not may likely not reach in your chopper application.
Here’s a simplified diagram suitable to make an SOHC run
