Paul,
This is exactly the great info I was looking for. Thank you Sir.
I like the idea of tightening and tighten again. Sneaking up on the vertical clamping pressure makes since.

Just had a thought, wish I owned a dial indicator and had use for one outside this exercise.
Wonder if this would work?
Dial indicator needle touching/positioned on top bell casting.
Tightening down rod nuts until the compression basically stalls the dial needle movement, then a little extra stretch on threads after a day or two of glass resting.