On the other hand, Karl-and as long as you're in "predesign" mode with your Snoozy...
How 'bout this idea:
Put the spare on the tongue, and move the generator
AND that awkwardly inside- stowed battery
to above the wheels (one on each side). No better place for that hundred-plus pounds of deadweight, which is all taken off the tongue where it presently is. (Some comes back with the spare, of course).
Seems to me like it would be pretty simple to slap a flattop fender/tray on those wheels. For "covers" one could even perhaps use something at least shaped like the existing fender, but with fiberglass sides that match the Snoozy.
Fastening for the cover could just be a simple hinge at the front/hasp at the back....