Finished up the adapter plate and mounted it on my lathe.

The holes for the mounting bolts are bored about .030 oversize. Since this chuck will be adjustable for runout, the holes had to be made larger to allow for movement.

Here's a picture of the ring that will hold the adjustment set screws. The ring is bored out to about .004" smaller than the chuck so it can be heated and shrink fitted onto the chuck. The adapter plate is about .030" smaller in diameter than the ID of the ring, again, to allow for movement.

And here's the chuck fitted to the lathe. You can see the 1/4" x 20 set screws around the periphery of the ring. There are 4, equally spaced around the ring, to provide radial adjustment. This allowed me to get the runout to under .001".

Someday I'll need to take a finish cut across the OD of that ring to get rid of the rust and pretty it up!
Chuck