Ed, if you have to use CA, or any other glue which can cause fogging or frosting, there are ways around this. One method, not 100% certain, is to give the clear plastic a coat of clear varnih or 'Future' before glueing it in place. Another, only really possible if the shaping/sanding etc can be done before fitting, is to attach it with PVA (white glue), which is surprisingly stronger than you might think. If none of these are possible then, for a curved lamp, for example forming the curve of the wing tip itself, cut the clear piece oversized, then sand etc. Allow enough area around the edges to blend this in, either with filler, putty, the old varnish/talcum powder mix, or even smoothed out PVA. When it's totally set and smooth, the 'unwanted' clear areas are paintes as part of theb 'solid' area of the wing, leaving a neat, clear lens.
The latter method can often be advantageous for difficult shapes and / or sizes, allowing a larger area to cement / glue and work with, and easier to blend-in etc. I once made an entire pair of wing tips in clear acrylic scrap, sanded to shape and polished. Once fitted, the lamp areas were masked, and the rest painted as normal - looked seamless and convincing.
Hope this helps,
Terry.