Good luck with it.
I've actually got a very interesting camera to microscope adapter set in my office somewhere. We don't want to talk about the stacks of boxes, etc, I'd need to go through to find it though. :-)
It's a rather dated device in a nice wooden box, and it came with a number of inserts designed for different eyepiece and lens diameters. It's probably an antique for sure. But, it's perfectly functional. I found it on Ebay when looking for a solution at the time.
I experimented with it quite a while back before deciding on a simpler solution for what I was trying to accomplish at the time (using a Nikon Coolpoix 950 that seemed to work much better from a vignetting perspective compared to models with larger lenses).
If I can find this adapter set, I'll take a photo of it for you. It was designed to be very flexbile in the types of camera lenses and microscope eyepieces you could interface with it.