Well I guess there is no more takers.
This handy little tool is used to expand the piston skirts so you didn't have to re-bore the block and replace the pistons. Usually it was done by chucking the piston in a lathe and using a knurling tool. New rings and a knurled piston and no piston rattle. I haven't heard of anyone knurling a piston in the last 50 years. This is a hand held unit. I've never seen one before nor heard of such a tool. Knurling made a cheap rebuild.
Bet you all wished you had one in your tool box!
Somebody jump in with a question.