John Carney said:

The shelf that the insert sits on has
six threaded nuts embedded into the table, 4 in the
corners and two on the sides. My guess is that screws
can be installed from the bottom of the table through
these nuts to create adjustabilty for leveling the
instert. Is this correct? What would prevent these screws
from vibrating out of level or vibrating completely out
of the table?

I own a Rousseau insert, I wish I had gotten the Rockwell instead.
But to answer part of your question, the 6 brass inserts accept nylon
screws from the bottom of the table, and are used to level the insert.
The friction of the nylon screws keeps them from vibrating out -
theoretically.


Greg G.