yep, one of the local garden centres round here sells the bahco equivalent.
i've often thought that not only would it much easier to make a handle in the field, but it'd be stronger too!
don't panic, i'll explain my reasoning.
simple fact, wood, "in the round" is several times stronger than sawn lumber. it's one of the reasons why cruck framed houses/buildings worked so well.
simple fact, getting the stump of a broken axe handle out of a head without powertools is a big job.
suppose you were out on your extended trip and broke the axe handle. in order to manufacture a replacment helve you need a sizeable lump of wood to split to ensure that the grain was orientated correctly. ideally you need the grain to be running parallel to the swing/strike. you need a sizeable lump of wood, but your biggest and best woodworking tool is currently inop'
so you take a mere sapling and start to whittle it down to suit the eye of you head, inorder to do this you take off the sides of the branch to take it from round to bullet/pear/oval shaped. you automatically start loosing the very part of the grain orientation that will most benefit your handle.
with the funky bolt through heads, you take a swiss army knife, and an allen key. you saw down a sapling with the sak saw, drill two holes with the sak awl, bolt on the head and you're ready to go.
i have tried making tomahawk heads in the field. trust me, it's not a five minute job as some survival books or websites or tomahawk manufacturers might suggest.
the significant issue perhaps for your highly skilled axeman, would be the question of balance. without a significant weight in the poll side of the axe, they must balance very poorly indeed.
so, all in all, perhaps a very good choice for a survival kit. i want one! just a small inexpensive one, obviously!
cheers, and.