I believe this is Mike C's pic -
In terms of the clip, I read that this is the correct stuff for the non-conductive material -
http://composite-laminates.com/canvas-C-CE-sheets.htm
And according to mac88chp, the correct thickness is 3/8" (0.375"). So I could buy a 12"x12" sheet and cut several of these out on a bandsaw if somebody could provide me with the correct dimensions.
Fabricating the bracket from aluminum stock would be the next project.