Hello again,
Did you try McMaster-Carr? (www.mcmaster.com)
And
You might want to be free thinking here.
Matt Colie

Chris wrote:

There is a ~ 1 13/16" cable access hole in the
base of the mast, currently covered by tape.

Where can I find some kind of plug or lid for
this hole? Any pionters would be appreciated,
Home Depot and Froogle failed me.

Thanks!