Will: I like your reply, It is weird how one comment can bring back details that you haven't thought of in a while. Your observation on the thickness of one blade of the double bitted axe versus the other blade.
Well that comment made me remember how my fater's double bitted axe had one blade for chopping with a thinner edge while on the reverse blade the cutting edge was sharpened for splitting with a more acute angle which would split and not lodge in the wood (easily).
By the way he always used "Rock elm" for the straight handle in his double bitted axe. For those that are not familiar with wood specaes "Rock Elm" (now extinct in this area) grew unlike its other cousins very straight with a lovely small crown on top. A mature tree would yield 4 or 5-- 10 foot logs to the first limb. The wood had a lovely salmon colour to it, and by the way don't try and split it, or try and break a board or plank, they would bend to the highest heaven before that would happen.