> Of course they keep making wood lathes bigger and bigger, and cutting a hole a foot deep into block, for a vase or somesuch, is a very big deal.
> Could be for something like that.
No, because only the wood handle part is long, the part that goes on the rest is short, so it's for leverage, not reach, normally you want extra leverage for a heavy chisel, or a parting tool, but the edge on that looks like a scraper, you don't normally need tons of leverage to scrape....
I think you are on the right track with metal forming/spinning tool....