I am in the process of rewiring my mid ''70s 31 footer as well. Just finished the AC side using a new Paneltronics board with polarity warning and dedicated breaker switches for outlets & charger. On the DC side, I have a good breaker panel, but am going to a battery combiner to make a starting and house set up instead of the 1-2-both switch. Also replacing all suspect wiring and connections and doing a diagram. Suggest no shortcuts on bringing shorepower aboard. Instal (if not there) a 30 amp plug receptacle with a circuit breaker and polarity light. As to charger, no problem running DC appliances while its keeping the batteries up. Suggest a 3 stage 2 bank chager of whatever capacity makes sense for you.