The tool in the photos attached was given to our secretary by his window cleaner, who also does house clearances. The tool is 11” long overall and stands 5 and ½” tall when clamped to a bench.
The business end is 2 and ¼” diameter and consists of metal plates with saw teeth on the edges. The shape is a pointed cone and it is revolved by the wooden handle. The only markings are the word ACO stamped on both the column and the horizontal shaft. Tony thinks this is a name rather than initials as there are no full stops or gaps between the letters. When the tool is turned the saw teeth would be presented side on to whatever it was guided into so would scrape not cut.
Any ideas what it is for?