Set of 3 patternmaker’s clamps, unmarked

Description

These are not marked as to the maker, but they’re undoubtedly from different manufacturers.  All are in excellent condition.   The largest will hold an object 31/4″ thick; the middle-sized one will hold an object 3-1/2″ thick, and the smallest will hold an object 2-1/4″ thick (measurements assume that jaws are at right angles to the screws).   The largest one has a jaw length of 2-1/4″, the middle one 1-1/2″, and the smallest 1″.  All are completely rust free and free of damage to the threads.