The skate sharpener quess seems to be correct.
http://cgi.ebay.ca/VINTAGE-SKATE-SHA...cmdZV iewItem

Pete Snell wrote:
Hi all

This object was in the garage of the house when I bought it 10 years
ago. I've kept it around even though I really don't know what it is. Was
doing a cleanup of the shop when I came across it again, and thought
that the good people of RCM might be able to identify it.
The half with the slots rotates relative to the half with the
circular cutter, and is indexed so the center of the slot remains in the
centerline of the cutter. I have no idea of it's age, but it's certainly
at least 10 to 15 years old.

Any ideas?

http://www.metalworking.com/DropBox/whatsit.jpg
http://www.metalworking.com/DropBox/Whatsit2.jpg
http://www.metalworking.com/DropBox/whatsit3.jpg
http://www.metalworking.com/DropBox/whatsit5.jpg