Why not buy a Factory shop manual & sit down & rebuild what you have & get the wiring for the electronic ignition from a donor or a vendor.

I have in the past robbed a harness from a 72-77 Dodge truck & made it fit to gain extra circuits.
73-84 Chevy truck harness can be cut down to fit & is actually the easiest. You get fuse links & all. You can use the 84-85 harness with OD & get the switches & harness to use for a 518 Just get the 2 pressure switches & you have a PATC style lockup kit