I finally got around to putting my mount design online.  It's at the bottom of my Engine page in the part that has been updated.  It includes a VERY rudimentary 3D drawing of the 13B that I will improve upon when I get to tearing the thing apart.  I included the STP on VRML 2.0 formats, which should cover most program's import formats.  If anyone would like it in a different format, I'll try to see what I can do.

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http://www.ernest.isa-geek.org/
"Ignorance is mankinds normal state,
  alleviated by information and experience."
                                  Veeduber