I just did this completely from scratch. While the simplest thing would be to replicate the original system, it's hard not to be tempted to perform some upgrades. Do you want to keep it 6V, include some fuses, add a passenger side light, turn signals, etc?
In my case, I went 12V alternator conversion, added relays and fuses way up under the dash (hidden) and a Ford style starter relay. but I re-used the original switches, light sockets and starter "stomp" switch. I used modern PVC jacketed wire which can be covered with black harness tape. So while some of it is obvious, it's subtle enough to not be glaring.
I'd definitely do it again. I found it satisfying to do myself.
Good luck!
PS if you'd like, I can post my schematic for a "modern" style system if you are going to lean that way.