Update:
I made some progress with the x axis. I mounted and aligned the ballscrew and the new riser plate. I was concerned whether there would be any binding. After aligning with my test indicator, I tightened up my dovetail, then torqued all of the screws holding he riser plate to the x axis, the ballscrew and mounts. I hooked up my test indicator and couldn't get it to move, everything is extremely solid. Next I hooked up my drill to check movement. Here is a short video moving the x axis over its full range:
Finally, I drilled and tapped the timing pulley and mounted it. The axis moves smoothly and without binding using the drill and by hand.
I am using a 15 and 25 tooth "L" timing gear setup.
I will probably get a shorter belt to keep the axis more compact. The belt was a left over from the mill conversion.
Thanks for looking