Okay, Mike unscrambled whatever was wrong with my permissions!
I've posted a few photos as "Navigation Light Color Restoration" in "Amphicar Restorations. Projects, & Repairs".
This isn't as nice as a installing one of Hugh's new fittings, but before replacing the navigation light, I wanted to try restoring the color.
I used Tamiya Clear Red X-27 and Clear Green X-25. There's enough tint in each of these little bottles to repaint dozens of Amphicar navigation lights.
I brought my light into D&J Hobby here in San Jose where the paint is sold. The guy there has done custom cast plastics, and thought the new replacements were a great deal, but was happy to recommend the materials and provide the following advice for this experiment:
1. NEVER shake the paint! Use those little stainless steel stirring spoons.
2. CLEAN the surface thoroughly! Finger-prints or dust will show.
3. Use a SINGLE coat! I painted it on fairly thick and "rolled" the liquid around until it set to get an even cover. Additional coats dissolve what's already there and it all gets lumpy; but if you mess up, another coat will soften the first so you can clean up and restart (like I did).
It works! I haven't tested this solution under the blazing hot summer sun, but ran the lamp on for over five hours (longer than I've ever run the navigation light!) and the tint was unchanged.