The bracket, that came with the Robo-Focus, was very easy to bend and attach to one of the viewfinder bracket holes.  The only modification, to the bracket, was a quick hit with a rotary grinder so the screw would fit through the slot.  Then all I needed were a few washers, for spacers, and a longer stainless steel screw.

If you need to also mount the finder scope, special brackets can be found by searching the Internet.