Erik Levin wrote: "The handle is hard rubber, about12mm diameter, and the
ferrules are silver or pewter. Total length with both ends installed is about
200mm. The blade is not sharp on the edge, nor does it appear to ever have been.
The edge on the oval end is also not sharp. Anyone recognize it?"
Looks a lot like a leather modelling/embossing tool. Not exactly like any I've
seen, but no more different than they are from brand to brand.
https://www.tandyleather.com/en/product/craftool-pro-modeling-tools

I like Alf's suggestion of wax modelling, except I think that all the wax tools
I've seen were one-piece metal. Or sculptor's clay modelling, perhaps, except
that the clay modelling tools I remember were much larger in their working
faces, and one-piece wood.

Tom ConroyBerkeley