Thanks. I have a lot more changes planned and will probably make a dedicated thread on it. I need to do a bit more though.
I sprayed Rustoleum Leak Seal over the plywood on the underside. I may brush something on later, maybe Rustoleum's product or FlexSeal. I sprayed the frame with the same product I use on my Jeeps to undercoat them - Krown T-40. I haven't had any problems underneath but I'm certainly keeping my eye on it.
The brakes work fine, no dragging, locking, etc. I had an old controller in one Jeep and the RV dealer put one in my other one. I can't recall the brand (I'll check my records) but they said it's the one they use on all of their installations ($85 or so). It worked fine and is easy to adjust as needed.
I smeared dilectric grease on a lot of contact points. I will also be adding a few junction boxes to the system to keep things organized and protected. Generally speaking I'll be covering all wiring, in and out, as I go. Next step is to set up the solar system. I have a 100W panel that will travel on the lid and be lifted off so I can follow the sun when camping. I'm trying to avoid having to replace the lid gas struts to compensate for the extra 25 lb. panel.
Hopefully you can add yours to this thread when you get it!