I've bought and sold a good handful of ladies legs calipers over the years, but don't believe I've ever seen a knock kneed pair!  So fun. And with a satisfying negative space created when the toes are touching, it feels like these calipers are happiest closed--the most modest of ladies legs! Made by a metalworker or machinist, who stamped their initials, EJG near the top of one leg. C. late 19th century I believe. 

5" t x 2 1/4" w when toes are touching. Good antique condition. Surface age as evident, but surface is completely smooth, not pitted/corroded--I have not tried to clean.  Tight but easy to open (all the way and back around again), holds in position.