I was able to get three of the four keys off my wife's Mustang but the last one is on there with a vengeance. These are hardened and have 5 raised areas on the 5 sided key. Four of the raised areas are about 6mm wide and the 5th one is about 4mm wide. The markings on the side are G661-1/2H. I called Gorilla and tried to contact Eagle but n.o help there. I am really stuck and am thinking the only way I might be able to get this off is to drill out the stud. I am replacing the hubs any way but having the key would be so much easier. You can see I have beat the crap out of the key with various size sockets, both metric and SAE and even a hardened, damaged nut remover but this thing is not budging. Ideally someone with recognize this and be able to tell me who makes the removal key.