Not sure if PT did a better job with the PT1850, but there is definitely nothing special about the wiring harness in my PT422. Low grade wire with cheap crimp terminals on it. No real wiring plan or attempt to logically and neatly route the wiring through the engine compartment, or under the dash.
Would be better if redone using marine grade tinned wiring and shrink wrap insulated crimp terminals.
Every now and the. I think about adding a real circuit panel to the beast, and redoing the wiring. Then I sit down, and forget the idea.
I probably should at least rerun therimary wiring between the ignition switch and the starter solenoid, which would probably help somewhat with cold weather starting, since I think the fine gauge of wiring doesn't help much.