The good part is that it's in tact with all the inner workings - most times we find either the frame, or a part of the "guts", but not often you find one complete!!
Definitely a colonial shoe buckle. With a small amount of internet searching you should be able to get a rough time period on that. With extreme care and some yankee ingenuity you may be able to get the parts to move.... but if you broke it that would be a real shame. Nice find though just found my first one recently and I count it as one of my best.