Bought a box of pliers at auction with many special purpose ones. Many "hog ring" or upholstery pliers. Here are 6 interesting ones. Number 1 is "Gripso" , 2 has an interesting tip on jaws, 3 has a v one one handle for tack pulling?, 4 has round grip jaws but a side set with cutting or other use?, 5 is W. Schollhorn Co. with a needle jaw and a flat jaw, and 6 has a removable curved jaw. What a variety!

What is the screw on the upper handle of the Gripso pair for? Any idea?
  Intresting group of pliers, nice find.

That side is two piece and pivots on that screw.

Several companies made versions of #1 including Gripso. 

That Gripso looks a lot the a Proto or P&C compound leverage pliers. I have two of the Proto ones and one pair of the P&C

EvilDr235

I think I can honestly say I have never laid eyes on any of those before.

Number 2 looks like Eagle Claw carriage bolt pliers.

Number 3 are probably Wm. Hjorth Lightning pliers.  I say probably, because I have seen other manufacturers. Hjorth is the most common.