I decided to take a chance and cut the plexiglass with a pair of sharp snips (no serrated edges). I started about 1/2" from the final cut line and worked my way in. My second cut was about 1/4" and the third cut was on the line. My final cut line was still about 1/16-1/32" from where I thought the lens would have to be to fit into the recessed area on the fiberglass. I then cleaned up the edges with some sandpaper, emery cloth, and a very sharp utility knife. I used the knife to scrape the finished edge smooth (knife peels the plexiglass leaving a smooth edge). By the way, the cutting goes fairly well until you get into the portion of the glass where the radius tightens. This area requires care.
I didn't do the final fit just yet. I am thinking the fiberglass tips will flex a bit when they are mounted on the wing. This could alter the dimensions slightly where the lenses must fit. I will accomplish the final fit once the tips are at least temporarily mounted. So for now, the lenses are close but not quite complete.
