>>893714any dense hardwood is good. oak works, but you need to seal it very well because of the open grain.
You also need some brass rod/wire sized for those holes to do it right. Shape the two halves of the handle with a different knife and file, drill out the wood handle from the center, so the holes line up, sand a little, drive the rod through, cut it off, peen the ends in, and sand, and seal.
Last time I did this i used a nail (soft steel) which was a pain to peen and worse to sand flush, but worked. also, couldn't find my ball peen hammer, so used a cross peen one. meh.