Here's an interesting What is it....

[Sudsy]

So what the hell is it ??

[Jeff from Wisconsin]

Only a guess but might be tool to remove those decorative nail in studs/tacks that upholsterers use to finish off their folds, sometimes hundreds just one chair or couch. Guesses are allowed right? :-)

[Sudsy]

Thought that too but the edges are too thick to get under a tack or nail

[Papaw]

Looks like a split nut driver for saw handles.
http://positiverake.com/the-perfect-split/

[Sudsy]

Nope, too thick, wrong configuration
I'll put up a photo of the tip as soon as my phone / camera is charged

[amecks]

A tool for adjusting ignition points, magnetos, or voltage regulators?
Al

[Sudsy]

.

[humber2]

A tool for adjusting ignition points, magnetos, or voltage regulators?
Al

I'd say it is for adjusting typewriter keys or relays in an old telephone exchange.

[turnnut]

 ??? replacing spikes in golfers shoe ???

[Aunt Phil]

It's one of the tools you walk around a job carrying it in your hand trying to look like you're worth the paycheck till somebody asks where the hell you found the old ****** cause they been looking for it for 5 years and can't find a replacement.

[lptools]

Bicycle/motorcycle spoke wrench?

[Jeff from Wisconsin]

Thought that too but the edges are too thick to get under a tack or nail

wow you got that right, looked like it was maybe a 1/16 thick from the first 2 pics.

[Sudsy]

Bicycle/motorcycle spoke wrench?

The opening is 3/32 wide. Probably too narrow to be a spoke wrench

[Bill Houghton]

It's a dieter's spaghetti fork: you can hold only so much spaghetti on it, so it helps you lose weight.

[cody6268]

Looks like an old flat head screwdriver someone jerry-rigged into a nail/staple/tack remover by cutting a notch in it in my opinion.