The tip-up example that these were tested fitted to seen here is my build and both the owner and I were seriously impressed by the fit and quality of these glass parts, the lower panels are magic, they fit so well and are really hassle free (especially compared to what is commercially available out there). The parts are all a dense aerospace quality but extremely light, like the excellent intersection fairings he supplied us.
I am a bit pedantic about the finish of the interior and am so pleased that something came along that works for me and the owner. In terms of how to get the upper panels to fit over the latch mechanism - after Jan's rough cut (a concept that would work just fine btw) I looked at it again and am seriously considering a trim along the molded line of the panel to remove the wall cladding but retain the arm rest shaping and still cover for the posts and mechanism. If necessary the open wall on that side can be upholstered and the opposite side made to match...possibly trim both sides that way although I really like the fit of panel on the opposite(right) wall where it neatly hugs the backrest post and can be trimmed for the WD-617 tube.
As he mentioned the mechanism sits behind the backrest and is out of the way anyway.