[Logieberra (Logan)]

After reading this

'if I rotate the scope to DEC +15 on the meridian, grab hold of the counter weight shaft and apply modest pressure I can clearly rock the RA axis enough to visually see the camera on the end of the scope move back and forth relative to the ground'

From the SB document, Replacing the Paramount MX Worm Block Assembly:

Centering the Worm Block
To ensure the worm teeth are as centered as can be on the gear teeth, ensure the 1⁄4-20’s are tightened while lifting up and engaging worm block. You will need two 3/16 allen wrenches.
1. Ensure 1⁄4-20 screws on rotate axis are loose.
2. Lift up on worm block, and engage worm teeth with one hand, and rotate the gear
back and forth with other to ensure teeth are sitting inside each other and not on
top of one another.
3. There are two ways to tighten the 1⁄4-20’s. One way is to have someone help you
by one person pulling up on worm block with both hands while the other person tightens 1⁄4-20’s simultaneously. The second way is to pull up with both hands, then while holding worm block in place with one hand (not letting go of both at once) and tighten the right side first which will keep worm block engaged. While holding that screw tight with the wrench, tighten the left side simultaneously.
4. Make sure the 1⁄4-20’s are nice and tight. They can then be tightened a little more while the worm isn’t engaged.

Worm 'centering' is via 3/16-inch bolts #3 and #4.

P.S. There is slop when in lock mode. That's normal and intended. I assume you're in tracking mode here when you see the RA slop?