ToddsPoint --
Because I don't understand this, why would it not be fairly easy to make a wedge with a low-angled, tapered end out of bone ? Set the edge in the hinge & drive it with a tap on the other end.
Or butt a thicker, say 45-degree angled edged one up against the shoulder of the hinge remnant & drive that.
Seems like either way you could pop the hinge without leaving any trace of metal.
No ?