I made something similar for an 8x20 Korona. I used a 1/4 inch diameter brass rod that passed through 2 fittings that I attached to the front and rear parts of the camera. The fittings had small holes for the rod to slip through, and thumbscrews to tighten it down. I found that it added a lot of stability and the Korona I had needed all the help it could get.

Richard Wasserman