On Tue, 20 Sep 2005 11:55:58 GMT, "Dave Plumpe"
wrote:

Ummmm, perhaps I'm not understanding. I get the picture of a rectangle
formed by 4 brass rods, threaded on their ends, and connected at the corners
by 4 internally threaded brass "L"-shaped corner brackets.

At least one of these connections would have to have lefthand threads,
wouldn't it?

-Dave P.
Make it like a picture frame clamp where each corner piece has one
threaded hole and one clearance hole counter bored for a grommet nut.
Gerry :-)}
London, Canada