I bought a $40 Tosagata at JWW like the one below and decided to do something about the handle.
I looked around on the web and found a pre-made (and pre-drilled) pakkawood/ebony handle at EE for $45. I was hoping to use the "burn-in" method of attaching the blade to the handle, but was advised that I'd need an oxy-acetylene torch to heat the tang quickly enough to avoid overheating the blade. So I went to Plan B. After a little grinding on the tang and a little filing in the handle slot, I filled the slot with Gorilla Glue and pushed the tang in, being careful to align it. Worked like a charm. I was thinking of using epoxy, but couldn't find anything thin enough to flow into that small slot and fill the handle. And the Gorilla Glue is made for furniture, so I'm hopeful that it won't be too brittle for this application. The knife is made of (unspecified) blue steel, allegedly hardened to Rockwell 63. Takes a great edge, and it feels really good in the hand now.