Steve - pictures of the back of the box are something else I didn't take. :frown: I've already dropped them off for the auction, so I'm not sure if I can get access to take a pic, so I'll just explain it (you're pretty close in your assumptions!)
I did a 45 degree chamfer on the top half only on the back. I left the bottom half square. The hinge pin is set roughly 3/16" in from both the top and the back - it's not centered height-wise in the top piece, it's above the center line. This way, the lid rotates slightly up when opening, making it where only the small chamfer is needed! If you look closely at the picture of the open box, you can see the small chamfer - that's all I did! Let me know if I can clarify this any further!
If I can get back to snap a pic before the auction, I definitely will. Or maybe I can find out who the high bidder is, and ask if I can get a pic!