Barry
One option is to cast the part in place using JB Kwik Weld. Find a nut that has the correct thread size for the driver screw. The nut is probably metric. You may need to file down the sides of the nut so it fits into the hole. Run a screw through the nut, and use the side rod to hold the nut in the proper spot. Make sure the screw is perpendicular to the face of the driver. Use washers so the nut is flush with the outside surafce of the driver.
Them working from the backside, use a toothpick to apply just enough JB Kwik Weld to hold the nut. Let the JB cure. Remove the screw so you can get the side rod free. Coat the screw with WD 40 and screw it back in. Tape a piece of cardboard covered with wax paper to the back of the driver. Then fill the remaining volume between the nut and the hole with JB Wik Weld so the nut is solidly in place.
I have never done this for a driver, but I have done similar things for truck bolsters
