Hi David,
Which version of CC are you using? On my machine it is "Adobe Bridge CC" and for that I need to put custom panel in "C:\Program Files\Adobe\Adobe Bridge CC (64 Bit)\Custom File Info Panels\4.0\custom" but for CC 2014 you have to place at a common location which you are doing correct.
If you are using CC 2014, I will let you know the correct location tomorrow.
-Sunil
