Already got it installed! Even my hubby was impressed by it (this is a huge deal!!!) He even asked shy don't I keep the helmet for him- told him I would if he'd let me make him a costume- well, guess he didn't want it that bad but I'm making progress. Any how, it looks totally cool and was pretty easy to do- I'll be all set to do another when I get a smaller helmet.
**Edit**
Here's the pics of how it was installed:






And video of how it works:
http://www.mirax.iwarp.com/jangofett/rangefinder.AVI