65 Barracuda Complete Wiring Harness New?
You could just replace the wires one at a time. Lay the harness out like this on a piece of plywood and locate it with some finishing nails. Reuse all the plastic connectors, just use new terminals.
Wrap it with non-adhesive electrical tape when done.
I don't see where it would be more (if any) work than screwing with the painless (painfull?) kit.