Never saw one of these -- what is it?

[Branson]

This just popped up on eBay.  Seller doesn't know what it is and neither do I.  Anybody?

http://www.ebay.com/itm/SMALL-OLD-CAST-IRON-CARPENTER-FINGER-REST-TOOL-OR-PART-NOT-REALLY-SURE-WHAT-/261322517494?pt=LH_DefaultDomain_0&hash=item3cd8092bf6

[Lewill2]

Leather slitter.

[wvtools]

That type is called a lace cutter, used to cut laces and thin strips of leather.  They usually go for around 20.00.

[Branson]

Thanks for the ID.  It's now on my watch list.

[Billman49]

Note the blade made out of a piece of old hacksaw blade with the teeth ground off....

Larger versions, known as ploughs, were used to cut straps and belts from thicker leather...