The actual shaft diameter 3/4" of miter saw clamp assembly
The bottom of 630065-00 clamp has three sections. miter saw clamp slides into a hole in my saw, turns ~90 degrees to lock it in.
The very end of the bottom of 630065-00 is .630 with a flat cut off on one side to allow it to enter the hole in the saw that has a section that protrudes to hold the clamp. This section is .368 in length from bottom toward the top of the clamp round bar. The bar then is cut to a length of~.248 in length.
At about the .248 from the very bottom of the clamp, a groove (step down) is cut into the bar that reduces the diameter to ~.472 for about .255.
The main round bar is .684 in diameter.
Reverse the clamp to address the wing nut blocking the blade when mounted on the left side.
Do it at your own discretion:
Remove the rubber foot.
Use a flat head or T30 star to remove the screw holding the bell cap on.
Screw back in the opposite way.
Use channel locks to remove the ring (to ensue you don't bend it).
Put back together.