The water system is almost certainly not nearly as complex as you may think. If it were me, I think I would go about reinstalling or replacing the water lines. You may (or may not) be able to get some help from Coachmen about the routing and configuration of the plumbing; otherwise, you probably can get some help here with specific questions and pictures and so forth.
The bulk of the system isn't all that much different in overall design from a normal house water system, for what it's worth; there's basically a set of cold piping and a set of hot piping supplying all the fixtures, with the source of water (the city water connection and the pump) at the cold side. The hot and cold systems both probably have low point drain valves, and there's probably a set of bypass valves near the water heater. That just leaves the fill and winterize and pump/city water connection plumbing, which has a few variations.
The water system control panel on my Coachmen is merely a bunch of valves mounted together: the hot and cold low point drain valves, a fill valve (that connects the cold side of the plumbing to the fill line of the tank so that city water flows in), an "operation valve" that I believe is between the pump suction and the tank output, and a "winterize" valve that apparently is between the winterize suction inlet and the pump. Aside from somewhat unusual naming, they aren't that complicated to work out. I don't know if you have the same sort of setup or not.