hi Lewill2,
I went thru Shockley's 3 books this afternoon, wow.
not sure if I can help, but will give you my opinions, if I may.
PIPE WRENCH; 460591 is close, patented on Oct. 6, 1891. yes, it has 2 round contacts.
will get back to that later.
MONKEY/PIPE WRENCH:
746643 patented on Dec. 8, 1903 by John T. Myers, Gulmersville, PA and assigned
1/2 to Anton Hartig, Tarentum, PA
in the patent, the shape looks close, enen the outside curves of the top head. the real
change that I can see is the short lever to lock in the track is on the opposite side. your
picture shows it at the monkey side whereas the patent shows it on the pipe side.
this is only my observation of patents and the finished product. the patent is issued on certain
aspects of the item. I have wrenches with patent numbers on them and there are features on
the patent that is not on the wrench.
after they receive the patent, sometimes time goes by before they get to making the wrench
and they have changed their idea as how they want the finished product, or another way to
make it easier and cheaper.
NOTE; THIS IS ONLY MY OPINION.
you can check DATAMP for pat. #
if I find other info, I will pass it on. good luck, Frank