woodworking with epoxy .Here my source of almost any hardwood except birch, alder or maple is the lumber dealer , so kiln dried white ash. Less than ideal. Either way, laminating or steaming, I'll need a mold.
For what it's worth,(not being any authority on hafting),i'm with Square_peg.
The above sounds like the classic case of overthinking the issue.
A tool haft is a working structural member,living,you may say,flexing,absorbing dynamic loads.
As such it don't like to be overly stiff,or overly slick/furniture-like,or overly difficult to replace,being expendable of course.
We all know hickory works,so i'd personally go to the nearest box-store(curse be upon their names,and all their descendants to seventeenth generation),and pick the cheapest/clearest/rightest grain-orientation stick that'd fill that eye.
Hope(that springs eternal anyway)that this stick's been air-dried...
Shape it approximately,and boil the business end in an old coffee pot,with a rag preventing water to boil away too quickly.
(It's much kinder on wood,boiling vs actual real to goodness steaming).
Then jig something up,like restrain the ends and reef in a bend with some filthy old C-clamp,carve out a 2x6 say to the bend outline,screw it down to a surface and pull the bend into the concavity of contour.
(all of the above Has been tested,results guaranteed

).