I replaced 100% of the wiring, receptacles, fixtures and systems. I stayed with my mantra: keep it simple. It’s not what you take with you, it’s what you leave behind.
On the DC side of things I switched from a single 12 volt battery located inside the trailer to two 6 volt golf cart batteries wired in series and located outside on the tongue in a metal locking box built by Torklift. I used marine thru-hull fittings to run the battery cables to the interior.
I built an “electrical locker” under the front portion of the banquette. This locker is vented to the exterior to provide cooling air to the Intelipower (model PD9245C) power converter/smart charger that provides AC to DC conversion and smart battery charging in a small single package. I used a nice compact fuse panel from Parallax Power Supply and a simple bus bar for the circuit negatives. I have six DC circuits running throughout the trailer. Power from the tow vehicle when towing comes into a basic terminal block and charges the batteries and runs the running lights, turn signals, etc. I also installed a shunt for use with the Tri-Metric battery monitor that I mounted on a bulkhead. There is plenty of room for a future portable solar panel installation. I have no need for a power inverter.
I built a cabinet at the rear of the trailer in the bathroom for the AC power panel. Most power pedestals in campgrounds are towards the rear of the trailer so locating the distribution panel at the rear keeps wiring minimal. I ended up using an RV combo AC/DC box for the AC circuit breakers simply because it was, non metallic and non corrosive, lighter and in the end easier to install than anything I found that was small and AC only. It has four breakers: 1 for the main supply, 1 each for the outlets on the street and curb sides respectively and 1 dedicated to the air conditioner.
As far as “amenities “ wiring, I had no desire for a wired tv or audio system. Lap top computers and cell phones are more than adequate for us on the visual side. A Tivoli table top receiver, with detachable auxilliary speaker for good separated stereo, allows me to hook up and play high resolution audio files with a cell phone sized Astell&Kern digital dac/player and is adequate on the audio side (in fact, probably because of the curved surfaces of the trailer, this system sounds full and very satisfying).
After using the trailer now for a good period of time I do want to install an exterior antenna for AM/FM reception. Eventually I will also get around to adding a cell booster. Otherwise, I am very happy with this clean, simple arrangement that has lots of capacity for adding on if the need or whim arises.