I assume this is Cahill's plier ( patent 596572) It doesn't look much like the patent drawing but is the only patent for Jan 4,1898 that has any resemblance to a plier. Datamp says it is not known to have been produced which is understandable since only connection is pat date. No manufacturer mark at all. Can anyone confirm this is Cahill patent plier or did I get off at the wrong station ?

Jimwrench,  I believe that you are on the right track.   I checked the patent and read the write up on it,  the jaws look darn close to yours.

one thing that I have observed in patents and the finished product is they mfg. them close, but not exactly. there are many factors involved
in the process.

back in the early days, someone will come up with an idea, but they do not have the know how or equipment to put out the product, and the
patent office needed a model to study.  now you contact a company like The Ideal Machine and Tool Company of Cincinnati, Ohio, I have a
small booklet put out by them in 1912. called, "Inventers guide to $ucces$"

on the inside cover;  this little book is based upon many years of successful experience in inventing, perfecting, manufacturing and marketing inventions of all kinds.

they made many patent samples for inventors.  lets say you sent them your idea of that tool, they made the 1st tool for you, then you received
your patent, now you shopped around for the best price to mass produce them.  the company that you chose, may have a different method
of mfg. hence the finished product may not exactly match your original tool, but gives the same results in its work.

note;  you may have the original tool, as the inventor may have passed away or did not have the capital to market them. some inventors
just went and sold their patents to a company, some chose to collect a royalty.

back in those days, the only communications some had was a radio, (no computer to guide them in the right direction."

this is just my thoughts on this subject.   good luck.   

Searching the Google patent database, I've been unable to find any other similar tool that was patented on that date, so by process of elimination, I do believe you have an example of Mr. Cahill's work.

It is odd though, that they didn't even cut the V-notch and finish the form of the nail claw...? Perhaps the tool as produced was targeted at masons or some other trade and not folks who erected wire fences?