Well I'm doing this job myself with the help of my nephew who is a very good carpenter. A friend of mine has a large storage building with 12' overhead doors and he is letting me use space to do my project. Being an architect and engineer, I can certainly figure out how this roof goes together and how to rebuild it. I am also a master handyman myself. If I can renovate, rewire, plumb, new heating system, roof, windows, doors on a 1875 Victorian house; I can certainly do this. I have also done a few corvette restorations. I found a couple cut away details by Winnebago that show how the components go together. I don't see where this will be hard at all. Just my time and materials. I ordered the epdm and installation materials from PPL Motorhome in Texas who had a great sale, no tax and $9.99 shipping to NY. I'm only in for $5oo so far. I just need some luan plywood, rigid insulation board, glue and some other misc materials. I should be able to do this for about $1000.
To answer one of the other questions - no I'm replacing the entire roof structure, just some roof deck panels. There are aluminum roof cross rails that tie the walls to the roof, like rafters. These will stay in place. The sandwich panels fit in between the cross rails. The existing fiberglass roof is just a skin that peels up. No different than the epdm, just different material. Whether it is fiberglass or epdm will have no impact on anything.
It will probably be December before I start. When I do, I will post some pictures of the work.