Buy new cutters, make your own handles.
A worn out screwdriver, a hacksaw, a file, and a small drill bit.
A propane torch is helpful if the shank of the screwdriver is brittle enough to snap when bent.
You can buy a bunch of cutters for the price of a couple handles from Dembart or whoever.
You could do lots worse, than to find a copy of Gunstock Checkering and Carving by Monty Kennedy. Lots of good info from several experts, and lots of info on making your own tools. Lots of pictures of everything from basic to really ornate jobs done, too.