Fixer-upper: First the roof

[Catherine+2]

A couple of years ago I bought a 1965 (I think) Sears VIII pop-up for $200.  I think the owner's wife would have paid ME to take it away, if I had only negotiated with her! Anyway, when I was a child my family camped in a tiny tent-top camper that my grandfather built, so I wasn't at all concerned that the Sears VIII is bare basic.  It's HUGE compared to our old "Thompson Tent" camper, but small compared to most modern PUPs.  The topper bothered me a bit, though (our Thompson Tent had fold-out wings of marine grade plywood, no plastic that could deteriorate in UV), and sure enough, that is the main failure point.  After 40+ years, the plastic (not fiberglass) topper is just disintegrating.  I'm thinking I can maybe build a new top out of a couple of sheets of marine grade plywood with a waterproof membrane on top, edging it with the existing metal-work, but I thought I would ask for opinions, options, and alternate ideas here before I start on it.  I'm a single parent of 5-yo twins, so cost is always a MAJOR consideration.

Next I will have to repair/replace the canvas.  We live in an alpine desert, so the original canvas is in surprisingly good shape, we successfully camped in the trailer for two summers before the roof developed real holes last fall.  One end has some rot where the fabric was pinched when the top was put down incorrectly many years ago.

Catherine