After lots of useful advice from this forum (thank you) I went ahead with my project. It included a Renogy 100x flexible panel $200, a Xantrex C12 controller $92, aluminum channel from online metals $70, 50' of 10 gage boat cable from genuine dealz.com $55, 3m VHB tape $35 from Amazon and misc bits from Lowes $? and a lot of TIG welding from my son in law.
I picked the Xantrex controller as it was the only one I could find that let me adjust the bulk and float voltages to exactly what Trojan recommends for my battery
. It's mounted under the bed with the rest of the electronics.
The panel is quite flexible, a hair more than 1/8" thick and very light
. Renogy says it weighs 3 lbs; I didn't weigh it but it seemed to weigh about as much as the cardboard box it came in. We built a roof top frame with a channel that the panel slides into. It can be taken out and mounted in a portable frame on the ground if we camp in the shade. The 50' of cable was enough to go from the controller to the roof plus make up a 25' extension cord if the sunny spot is more than 7' from the trailer.
The rear cross piece of the frame is removable.
The strip of wood down the center was necessary to guide the middle of the panel into the channel.
The roof of the Snoozy is curved in both directions but the aluminum channel was easy to bend to fit. The VHB tape sticks amazingly well. The particular type, 5952, was recommended by a 3M tech support guy. He even called back a week later to see if I had any more questions!
The wiring runs from the electrical
opening for the shore power cable under the nose under the trailer and up the rear wall to the panel. It looks a little 'busy' but there are no holes in the roof and the MC4 connectors need to be available to use the extension cord. The cable goes up the rear wall in a plastic conduit box with a snap on cover meant to neaten up computer cable runs.
No performance info yet but we are leaving tomorrow for a month of camping so I'll have some data soon.