I think our best clue to the maker may be the "HEC" in Charlie's grip. Note that the first stroke of the "H" is done with the same hand as the "7" in Lee's grip. Note, too, that there are also similar pen or pencil marks (on the horn of Charlie's and around the metal circle of Lee's). I also believe that Lee's grips may be one of the earliest from this maker because of the added metal circle as he experimented with one of the most difficult parts of the grip to fit to a gun. He put the grip,without the circle on the gun, marked the position of the semicircle with his pen and then added the metal half circle.

Bob