Well, I've decided to give blademaking a try, since the good folk at the local John Deere repair shop were good enough to give me a handful of lawnmower blades. (And yes, I know all about the problems with working with mystery steel. Worst case scenario, it'll be some good grinding practice on free steel. Who knows; I might even get a workable blade.)
I've decided to make a Nessmuk knife, as described in George Washington "Nessmuk" Sears's 1884 classic "Woodcraft and Camping".
The following photo shows (top to bottom) an enlarged scan of Horace Kephart's sketch of the original Nessmuk knife, a cardboard template of that profile, a scaled-up version (Sears was five feet tall; I'm a bit over six), and a modification of the scaled-up version that hews a little more closely to the blade profile of the original and fits my hand a bit better.
You'll notice that the two modified versions have a little belly to the handles. I can't quite tell from the Kephart sketch, but I suspect that the original knife had a stag crown handle. This should make for a more secure grip.
Not shown is the steel I plan to use; that's currently annealing in a container of lime. I'll post a picture of it later.