Did you drill the hole in the case or does it come pre-drilled? Pretty good idea, gives the angle option.
All the camera's I've seen have the 1/4-20 threaded hole on the bottom and the Moultre's I have even on the bottom and rear housing. The problem with this design is I think I'm going to have to carry a couple of wrenches in order to get things tight enough. I may do some looking for bigger wing nuts and some type of locking washers.