Just saw this item, and it puzzles me because I think I've seen one before.  http://www.ebay.com/itm/Antique-Spreader-Tool-Metal-working-Auto-Body-No-Reserve-/221200859724?_trksid=p2045573.m2042&_trkparms=aid%3D111000%26algo%3DREC.CURRENT%26ao%3D1%26asc%3D27%26meid%3D6343985136243562075%26pid%3D100033%26prg%3D1011%26rk%3D3%26sd%3D221201465286%26

Looks like a valve spring compressor, but the ends would need to be more parallel.

Sure looks like a spring compressor of some kind, that's the only one like that I've ever seen. Maybe it didn't work very well because of the angle of the jaws and never became too common but that then makes you wonder how it got into production to start with. Makes me think it must be a specialty tool designed for one specific purpose.

Definitely a spreader. It can't compress anything.
Maybe there are steam valves that need to be stretched to disassemble, but I never saw one.

I am thinking buggy springs. Maybe early auto leaf springs?
Spreading leaf springs open to grease them has been tried occasionally.
  It attracts dirt and soon they squeak worse than they did before you started.  But people even still try it once in a blue moon.   

When I was young I had a buddy who spread and greased Jeep springs and then wrapped them in tape like a cocoon. He left town so I never heard how long it lasted.   I doubt it lasted long.
If it did springs would come with zerk fittings to grease them from the factory.
    yours Scott
   

It looks like a valve lifter that is open too far.  He does not have a good photo of the jaws.  I do not think it is a spring greasing clamp. 

It was common practice on Model T era vehicles to grease the leaf springs to help it ride smoother and the springs to last longer.  I am guessing that an improvement in spring steel made that practice obsolete.  There are several styles of greasing clamps and that tool does not look like any of them.  Member 1930 probably knows more about them than I do; perhaps he can enter his two cents worth in this thread.

valve compressor, very crude, but old springs didn't have as much  "squeeze" as our new fangled ones.

spring greasers look quite different, I'll get pics next time I have the box out,

>valve compressor, very crude

Ditto, vlchek made one somewhat like that..

Variations, similar, unknown pat pending (greenfield??), vlcheck

In the old days the valve springs were in the block and room to work on them was different on each model car/truck and there were a lot of compressers made to fit ......................................................................   bob w.

My vote is valve compressor also , very early teens era. The springs were weak and the keepers easier to get out than later engines. Many early engines had vales exposed with oiling cups. They needed frequent service.
I  believe this is the era this was used on.

 "I am thinking buggy springs. Maybe early auto leaf springs?
. . . .
When I was young I had a buddy who spread and greased Jeep springs and then wrapped them in tape like a cocoon. He left town so I never heard how long it lasted.   I doubt it lasted long.
If it did springs would come with zerk fittings to grease them from the factory."

Some cars DID come from the factory with Zerk fittings for the leaf springs.  They had a wrap (not tape - it looked more like shrink-tubing for insulating wires) over the set, and a single fitting to fill the wrap.  I believe that someone made a tape-like material for fabricating custom covers, but I've never seen it.  I believe that the latest car I saw this on was an AC Cobra, a fairly early one, but I'm pretty sure there were others.  Use of single-leaf springs, and fiberglass springs, ended that idea.  My Triumph TR-4 had Zerks on the sheaths of the handbrake cables: there's something that would STILL be a good idea, if people only used them once in a while so that they didn't "freeze".

The technical term for the over-wrap on multi-leaf springs is "gaiter."  They go WAY back: see http://tinyurl.com/d2njvsj.  Note mention of ability to lube without removing them in article.  Indian motorcycles w/ leaf springs used gaiters with an oil reservoir, rather than Zerks.