This tiny saw I plucked--along with the heart clamp and stair saw also listed today--from a small trove and an antique shop in Midcoast Maine that I think all came from one collection. I think it could be called a pad saw, or keyhole saw, but it's an especially small one, made long ago for a very specific job I would guess. I'm not at all a tool expert, but I do appreciate a sculpturally satisfying, well designed thing when I see one, especially one born of necessity, and this to my eye is that--with beautifully worn, fat and flat end of the handle providing an excellent grip for executing a precision job with the long and narrow blade, which remains sharp. Feels great in the hand, and also seems like a handy thing to have in the tool arsenal! 

5 7/8" x 1 1/2"x 5/8". Lovely antique condition condition, wonderful patina, hand-forged blade remains sharp.