My setup is very similar. I made drive sleeves out of delrin and tapped them to 5/16 14 and 3/8 10. I made the stem that the chuck holds just under a half inch, and then made to end that the pin screws into bigger so it covers the pin and most of the face. I wanted to make sure i kept the face as clean as possible so i didnt have a lot to face off when i was done. For now, im done spraying clear coat. Im using a foam brush to apply both the epoxy base, and the ceramithane.
Joe
Joe