Brian, you are like MacGyver when it comes to lenses. I actually asked DAG if he could modify the Minolta 58mm f1.2 but he declined.
I use a pipe-cutter on the tubular leg of an old tripod leg and a retaining ring from a Russian lens to make the RF Cam. It must be polished down to the correct length. The retaining ring went into the inside of this one t build of the thickness for the cam follower of the lens.