physh1
+1y
I've got a few pics on my site...may not be as helpful as you want but it should help a little.
The c-pillars are hollow...nothing there. Basically, when we did it we chose where to mount the hinges and then built a structure/frame around them. We used all 1/4 plate steel and built a honeycomb structure of sorts. I'll see if I can dig up any good pics...
Cameron