Shouldn't be too hard to make one, I might give it a try myself, after it turns it should match the stock of a TC hawken kit I just put together. I have burned a dump truck load of osage scrap probably some wood wood for a ramrod.
I have made an arrow or two out of it, seems like the bare shafts weighed 800 gr or something like that.
Herein lays the problem; grain runout, perfectly straight grain osage is like finding a unicorn. Straightening osage is a piece of cake, much easier than straightening hickory. I heat it with a paint stripping heat gun first to the point that I can barely touch it, then straighten it like one would an wood arrow shaft.