I bought a box of Ford "T" tools at auction and this was in with them. Marked "Wm. Johnson" on one jaw. Jaws spread and close with slide. Offset in jaws with teeth inside. Have never seen one of these, but it may be common. ??????

In fact, a plumbing tool, a basin wrench.
William Johnson ,  Newark,New Jersey is listed in Iron Age (1911,) as a seller of wrenches, and might perhaps also be an inventor (I see patents, but not sure about that)

Oddly, the same Issue also lists him as maker of Oyster and Clam knives, and can openers....

My dad picked this little guy (also marked Wm Johnson) in Indiana this summer. When I tried researching it I figured out that they were incorporated in 1931 and were bought out in 1958.
Found my info here: http://www.mgexperience.net/archive/Mystery_Tool_Quiz/1148476

That is a plumbers pipe reamer. Made for lead pipe.
Its not strong enough for steel pipe, but it will still do copper, or plastic pipe like the bomb!
One or two good twists, and its clean, bevelled and ready to rock.
After you sharpen it back up of course.  ;) 
Its not hard to do.

When these are sharp they will cut wood effortlessly too.  All you have to do is dream up a situation where you need a really fast tapered hole.
  yours Scott

>All you have to do is dream up a situation where you need a really fast tapered hole.

You haven't seen my last attempt at making a peg.....

I've never seen a basin wrench like that, now I got to find one.
(would have never guessed what it was either)