I'm guessing this is a plane of some sort, it was in some stuff that was passed down.

Saw jointer-  used with a file to even up the teeth prior to setting & sharpening them. 

Hey thanks, wasn't even close was I :-).
Any idea of the age?

The screw clamps down on the flat side of the file, then the file is guided along the tops of the teeth to joint them before sharpening them.  Kinda like a jointer plane.

Plus, they are kind of cool to collect.
Every single person in the saw business made them. 
I suspect sad iron trivet makers, iron cook stove and probably locomotive makers put them out too.
Everybody in the iron business!

  There have to be dozens of patterns available, every single one at least a little different. From very plain to very fancy and often can be had for nearly peanuts.

Yup, saw jointers and saw sets can both still make large admirable collections for not so much money.

Trying to collect what every Tom Dick and Harry already wants? The popular tools?
That sux!!
  You get to find 2 a year if you are lucky, and hock your socks to get them.

  But find something you like that is relatively uncollected??
  Jackpot!
    yours Scott   

Add saw vices to the collection & you can corner the market.  Everyone also made them, all a little different & some very interesting

Thanks for the info., I see I have a whole bunch to learn.

Take a look in this 1931 EC Atkins booklet. It is in there. Bookmark the Rose tools site. Lots of old tool catalogs to download.

http://www.roseantiquetools.com/sitebuildercontent/sitebuilderfiles/atkinssaw1931.pdf