The attached PDF file illustrates a polar mount I'm designing for my 1.2M Channelmaster. I plan to use the original Channelmaster post mount/dish bracket and adapt .5" pillowblock bearings for the polar axis. Anyother parts should be available at any local W.W. Grainger and Lowe's store. However, I've found some brass bushings that may work better to reduce the overall size and will initiate another layout to see if they will work. The mount will be actuated with a 12" or 18" linear dish actuator and you'll need an old IRD receiver to drive it.
I'll be glad to share my design with those interested when I get it working.