Ron,
I searched for coffee grinder mechanisms some time ago in order to make a copy of my grandmother's coffee grinder for my bothers and sister. (I got the orignal after Grandma passed away about 20 years ago -- they always give me grief that I got the coffee grinder that we all played with as kids.)
I found what seemed to be the same mechanisms avaiable from a number of different sources. I ordered four of them -- they seemed to be well made, but I haven't yet made the case and tried them out to see if they really grind coffee.
The following Rockler link shows the mechanisms. I purchased the square version.
http://www.rockler.com/product.cfm?page=10756
Hope this helps.