It's not possible to remove the worm and wheel without removing the leadscrew, so photos and a few measurements will have to suffice, I'm afraid.
On a best efforts basis, here are some measurements…
Worm diam = 18.5mm
Worm-wheel diam = 48.8mm, thickness = 12.7mm
Thickness of drive gear = 14.4mm
As best as I could determine, the worm rotates 36 times for one revolution of the wheel.
Since converting the spindle and power feed to VFD I've never changed the gears in the power feed gearbox. The gears I use are the smallest one and the large one in the jaws of the calliper.
Hopefully you can determine the dog-clutch measurements from the close-up photo.

Edited By Gary Wooding on 13/04/2020 09:49:07