Besides, what this thema does in "warbow" escapes me.
I think TS has posted in this section because these tools were used to make Warbows in England.The only one I have seen was in a museum,it was a hefty piece of kit! Nothing like a scraper,I think Floats were used as we would use a Rasp or surform.
Were they? Because as far as I know we dont have any tools positivelly identified as bowyers tools of trade.
We have descriptions of operations for which workers were paid such as "chipping" - which is most probably shaping the stave by small axe and some which cannot be tied to the specific tool like "bending and afterbending" - yet there is none which would be positivelly tied to such a tool as above, much less on the split stave bow, where versatility in copying the character and treatment of knots would be preferable quality. (Frankly I dont even think that facete-like belly of MR bows is result of scraping - since that produces much better surface than that - but its rather a sign of expert handling of spokeshave.)
That is from position of somebody who makes also musical instruments which requires good deal of scraping where modern sanding is more or less prohibited.
If you ask me the tool above looks like some more modern tools used by cabinet makers for finishing veener surfaces on large areas such as table tops - which is something medieval cabinet maker would probably use to smooth out the last handplaning marks on something like table or bench, but all my experience in making bows says it is not very good tool for it.
To comment further - we have evidence of both rasps and specialised files with woodworking "single" cut both in archeological record and record of use in various woodworking crafts - thus if the rasp was needed, mediveal woodworker would take a rasp.
J.