Remembering the old adage of "never say never," the use of a pair of pliers in an 18th century shooting pouch was very uncommon to non existant, as I have been informed by very knowledgeable people. That doesn't mean a person couldn't carry one if they wanted to, though.
Pliers in the 18th century ranged from very crudely made ones to nicely made small blacksmith tongs to pliers that are still available today. I have a pair of original needle nose pliers that were fairly nicely made, but still hand forged, and they could easily go into the 18th century - though I think they were made in the 19th century. I also have found modern pliers, often made in Europe, that are the exact same pattern as those made in the 18th century.
While visiting the gun shop at Colonial Williamsburg, they showed me what they use to document all sorts of tools for their works. Diderot's Encyclopedia in the Iron Working section is great, but the VERY best book on 18th century hand tools they suggested is
A Catalogue of Tools For Watch And Clock Makers, John Wyke of Liverpool Almost any kind of hand tool a gunsmith or many folks working in the metal trades is listed. I can’t say enough about this book.
http://www.thebestthings.com/books/wyke.htmOK, so you asked for some pictures.
This has GOT to be one of the fanciest set of pliers I have ever seen and from the 17th / 18th century. :
http://users.wpi.edu/~jforgeng/CollectionIQP/artifact.pl?anum=1260Here is a set of reproduction tongs made for use in a bag whe you scroll down the page:
http://www.olddominionforge.com/other.htmlHere is a set of box joint pliers that could have come right out of John Wyke’s catalogue. (I found a set just like these and didn’t pay much for them. You may be surprised just how many box joint pliers you can still find that are correct for the period because they didn’t change them much, if at all.)
http://www.practicalmachinist.com/vb/general-archive/slightly-ot-box-joint-pliers-96004/Now, in this link, I found a REAL treat. Scroll down to the post by old-biker-uk with three pin vices and what looks like flat leg pliers. These actually ARE 18th century pliers/cramp that were used in many trades and listed in many shapes and sizes in John Wyke’s catalogue. I had never seen a real one before I found that link.
http://www.practicalmachinist.com/vb/antique-machinery-history/fantastic-early-hand-vise-207228/Hope this will be of some help.
Gus