John, I was thinking about your window again, after 'completing' my camper, and that we both used the Trim-Lok LK1660 gasket.
In my case, I installed this gasket so that the 1/4" channel (labeled '1/4" glass' in the manufacturer's diagram above) grips my window opening frame. And the channel the manufacturer intended for the body panel, labeled '1/8" edge' above, is where my acrylic window is installed. The 'lock' is on the inside of the camper, not the outside.
I recall reading in your journal before (and I think I confirmed again), that you used 1/4" acrylic sheet. Can you remind me which channel holds the window frame, which channel holds your acrylic window, and which side the gasket's 'lock' is on in your build? Not that I'm going to change anything, but I was just curious.
Thanks.