When I purchased my trailer, it was missing the big skylight cover. In the long run, I ended up making one from lexan and two different sizes of aluminum angle. I had a couple of the vent lifters mechanisms and they were utilized so the homemade vent cover operates just like the original was intended. Do you have the original lifter mechanisms? That would be all you would need from the original set up. I've got pictures around here somewhere. I'll post them to this thread.
4CU 2699 / AIR 10 / TAC AZ-1
I'm haunted by aluminum.
Charter Member of the 4 Corners Unit.