Hi Mike...
I checked my version of the Losmandy polar scope off my 15 year old G11 (for which I also am missing the illuminator), and I was surprised to find it is actually a metric thread, Scott is pretty good about standardizing on imperial/SAE threads on his mounts, but the threads for the illuminator on my polar scope are actually M6x1. If you do decide? to McGiver a new illuminator, please report back and let us know how it went.
Jeff
