I had been working on adding a couple more AGM batteries and a Xantrex Prosine Inverter/charger to our RT lately and it is now done finally. I put pictures and some info on my blog about it. Part of installing it involved taking out the original magnetek converter/charger that came in the RT. The pictures should help with anyone else who may be considering this. Of course if anyone has questions about it, I would be happy to answer them.
The Prosine was a used one found on Craigslist for $350 and worked perfectly. It is a 2500 watt pure sine wave unit with 3 way charger. I found the battery sensors on Craigslist too a few days after the inverter for $25 shipped. There are lots of great deals to be had if you do generic searches and check out all the results. This one was incorrectly listed as a "3000 watt inverter for $350". It wasn't till I looked further that I figured out it was exactly what I was after.
97 Roadtrek 170P "Taj Ma Trek"