Electrical issues - Mainly alternator based

[PbFut]

How original do you want to be. Do you want original battery meter to work as designed or convert to volt meter. Will you be using heavy load items like elec fans, off road lights or bags? All come into play when designing your system. Given you found damaged harness under dash I hate to be bearer of bad news but you probably should replace the harness. Cutting out sections leave compromised remains. Do it once and do it right.