Hello!
If it's only the paint you need to get rid of, you can use brake fluid - put the part in, wait half an hour or so, then rinse with water and scrub with a plastic brush. Most kinds of paint go off with no problems. Just be careful with the brake fluid, on the bottle it says it's toxic.
The glue is your real problem - it can really mess up plastic parts, because it doesn't stay on the surface, but penetrates deeper. You can try to polish it out - first sand the surface with finer and finer grades of sanding paper, then use a polishing compound or something like that. For the final touch you can dip the clear part in future or something like that.
Hope it helps - good luck with your build and have a nice day
Paweł