Okay, time to get a little serious here. Don't know if Jim Whisker published it, or not, but in a conversation once, he offered that Martine could have been the father of David Boyer and that the elder Boyer made many of the guns we mostly suppose were made by Haga, including some fine, early swivels. If true, that would account for David's good hand and certainly the swivels. Single shot rifles by him are not as elegant. Both lived in the area we think of as Haga Land and Martine was early enough. More research might clear this up.
Dick