Sharon and a few others building versions of pop-up tops have discussed the potential problem of lifting the top into place. Depending upon what you might put on the roof, the top might seem a bit heavy to heave. Depending upon age, height, and arm strength, the top might seem a bit heavy to heave, too.
Well, I believe David S has found the answer to the problem: 12 vdc linear actuators.
I have done a quick check on the options available and found one that may be ideal for my application, a 18-inch extension with fast activation up to 1.75 inches per second pushing 40 pounds. The model is FA-04-12-18 by Firgelli Automations and costs about $130. The motor and gearing are contained within a tube of less than 2-inches square. Way cool.
Also, quite by accident, the angle between the front of the roof and the attachment on galley counter is almost perfectly parallel with the front slope of my trailer. Now, I'm going to get CAD software to make precise calculations and plans.
It shouldn't be too difficult to make a fairly weather-proof seal around the extension tube, which is of small diameter. Since the angle between fully retracted and fully extended in my design is quite small, all that I should need is a simple rubber boot, perhaps with a slit opening if the angle proves too great.
Alternatively, I could do as Sharon is doing and extend an eve or eyebrow over the front edge of the pop-up roof. When retracted, the eve or eyebrow would sit firmly sealed on the roof behind a weatherstrip covered lip. In Andrew's original design for the Compact III, this eve or eyebrow is fixed to the roof, but then again it is at the hinged end opposite to what Sharon and I are doing.