I mentioned putting on gas struts before, but my "use and remove" actuator was, and still is, working good and I got delayed. I am now retiring that actuator to reserve status, as I installed the 2 gas struts yesterday.
Oyo, Tex, Fred, and others have described their designs and methods, and I put pieces together and have posted 4 pics to show, although I have little to tell that has not already been told.
Of note though, I did mount the top brackets so that the ball mount pin is higher than the frame right angle.
The bottom mounts are shimmed out with a piece of poly plastic and I lucked out by using #12 screws into inside framing except for 2 screws.
They are 60 pounders, and at first rise I thought too powerful, but after some use are now very smooth. When I release the second clamp, they slowly and gracefully lift the roof panels and snap them into place. Surprisingly, it is almost like watching a magic show.
I have a 2012 A122, and different models and year changes have some variations. So new candidates contemplating doing something similar should do much research from prior postings.
Again, thank y'all, and Happy Camping!