Alan, as you know, lots of mountain range people carried some form of a Bowie knife in the 1800s. In some cases a bigger knife is an advantage, as you can actually can carry a Bowie knife on your person, whereas a hatchet, saw, axe, etc is obviously a purpose built tool.
A neighbor many years ago was a collector of 1800s "mountain man" weapons and tools and had a lot of cool stuff for a young kid like me to admire at the time. He had a marvelous collection of the rifles and shotguns. This was one I remember:
http://www.historicalarms.com/colt-revolving-shotgun-for-sale.htmlIs your son's 12-9 a "clip point" or a conventional shaped blade? Has anyone ever field tested the two shapes against each other?
Tom V.