Probably not a woodworking tool but I don't know who else to ask. It's a brass conical point that a pocket knife blade folds into. Not often I find a tool I can't even guess at. Found in the lab of a geochemist.
it's the tool for sharpening a "cork borer" the brass tube hole cutters,, the tube is rotated against the cone while thumb pressure is applied to the blade.. a set is nice to have for cutting gaskets..