From what I could research, the patent for the alligator wrench was issued in 1876 and was produced into the early 1900's...
Used primarily to fit square nuts and for pipe fitting...steam engines and RR locomotives, farm equipment, wagons, and the like...
Depending on shape, condition and manufacturer, the value generally runs into the $20 to $40 range...
When in my teens I found a tool box full of them resting on a fireblock of a wooded-up stud wall in an old house my dad was renovating...
See them frequently in antique stores...
Great info. Thanks!