Randy: I think it was around 2007 when I had my Omega F head completely refurbished by Focal Point (in FL). Michael Sparks was very helpful and knowledgeable. I would think he would be able to help re: dichroic filters.

His e-mail was mike@fpoint.com and the url was www.fpointinc.com. Hope this helps. Feel free to let him know I referred you.