I'd call M&R since they made it. We bought many a bulb from Caprock over the years, until we went LED. It's a good company, and have been around forever. I used to buy halftone screens from them (how halftones were made pre-digital) back in the late '70's. The last time we had to get a new bulb for our Violux 5000s it was just under $200.00...
Steve