Nathan asked what the light tan item in the back was, and Rick Soller responded that it was part of a fuse cutout.

It just so happens that I bought a very similar piece from Roger Ziesak at the Linda and Howard Banks insulator show just 2 weeks ago, so here is the part Nathan asked about, plus some other examples of smaller units.

The fuse inserts into the cylindrical housing. Hope this helps answer the question.