Have you thought about restoring the harnesses? I just did mine. I removed all of the ragged tape, inspected connectors (all good), degreased it, removed no longer needed (******d) wires and then retaped it. I'm happy with how it turned out.
I'm doing the same thing. Nothing new here in my fleet shop we build and repair harnesses all the time. On mine I am updating the wrapping materials a bit but mostly cleaning, inspection and 4 new valve cover connectors. I think in is important to long term reliability since most every electrical gremlin you here about is some obscure rubbed or partially broken wire.