Rich, I have no idea who came up with the grip safety but here is mine. I believe the gun was likely made by Alexander Wilson who worked for Joe Manton but left to go into business for himself. Obviously it is a late flint gun, likely from the 1820’s. The safety is sort of neat but the “flaw” is that when the gun is carried normally—the right hand around the wrist and left on the forend I find myself inadvertently squeezing the grip safety, rendering it useless. But it’s a nice touch and since mine is a self priming flinter it sure adds a bit of safety while loading even though the gun is supposed to be on half cock.