Well, I got the rest of the headliner in. It is quite challenging and the cramped quarters don’t help much. I did remember a technique that I have used for laminate work and contact cement that really helped. If, after the contact cement has TOTALLY dried on the camper shell and the headliner, cover the glued surface of the headliner (every square inch) with a sheet of newspaper and leave some protruding out an inch or so. Then you can fit the piece of headliner into the spot it belongs and carefully line up the critical edges-the newspaper will not stick to either surface. Once it is in place and you are happy with how everything is, tilt the headliner back just enough to start slowly pulling out the newspaper. As you pull it out, apply pressure to the newspaper free areas to get them to stick. Continue pulling the newspaper out until that panel is secure. Go slow and careful and it works quite well.
I gluded one camper panel and the corresponding headliners at a time and went slow. I also dry fit the pieces with the newspaper in place to get a feel for issues I might have before I committed to the glue.
I did discover that the 2 “L” pieces that fit around the top hatch were a bit skimmpy-the trim piece may not be big enough to cover the remaining gap. I think I can patch it and I doubt it will ever be noticed.
Best of luck!