..the lack of a table or anything usable on the belt sander (there is one, but I didn't put it on) makes it so that the roughing and fitting of these handles is freehand (including the octagonals). If it came to just jigging things up to chase geometric perfection, I'd lose interest. the challenge of getting faster and more even at doing this by eye makes it much more interesting.
I don't really like making the handles, but it's hard to use the chisels without them. The blanks make it so that they can either be sized down on a chisel as-is (and the ones that I have that are fat at the bolster end I can introduce to the belt sander and thin them now in a couple of minutes and make them a little more interesting), or they can be turned like the typical sheffield octagonal handles and a bolster added.
The beech handles are from the very first wooden plane I ever bought (a plane marked carpenter that I bought in lancaster, but that was the owner's name and not the maker's mark). It wasn't worth saving, but the front end had no cracks or checks, and it yielded 4 handles. Smelled like an antique mall when sanded, too.