A picture is worth...
This is the OEM part I removed. This is the one I have un-potted and will be reverse engineering a schematic from. I took some pictures after I un-potted it, but they came out a bit blurry (shaky), so I'll take some new ones as I go.
EDIT: Okay, here is one of the blurry images and a few after I have cleaned up the bottom of the board. The top WILL be a challenge as it has that huge connector base. I can see that will take quite a bit of time to dig out the potting material. I will probably de-solder the three center pins and two side power connectors and remove them to make room to dig out and view the board a lot better. Looks like a two layer board, so it won't be too difficult to map out.
Enjoy!