Here are a couple of more speculations that would justify the straight edge.
Were the axe a timmermannsbijl then it would not only have been used for hewing but would primarily have functioned as a tool for joinery work being gripped right up there near the eye, but also swung with great accuracy.
On the other hand if it is a sparbilla then its purpose would have been to pare down small diameter spruce stems to be used as rafters.
When I envision it with a very stubby handle, say no more than for a one handed grip, then I imagine it being used by the sabotier or klompenmaker.
I suggest you look further into it before altering the shape.
Also the axe does not seem very thin to me at all but rather bulky and massive, what is it 2 - 2 1/2 kilos?
And my perspective on lapping and grinding comes not from any failed efforts, which I try always to avoid, but is simply a principled one.
Greetings,
Don Wagstaff
Last edited by D Wagstaff; 03/11/12 02:42 PM. Reason: refireing