You can also go to a good pro-audio music shop and ask for the filter gels that bands use for their stage lighting. A brand named Roscoelux is one that offers a diffusion material that is very close to the original "textured" looking surface of the stock lenses. Maybe the drama dept at your local school would have some also. Only problem-- expensive, but very heat resistant!

1961 Chevy Apache

"Never turn a knob to the left"