I believe it to be a reenactment piece due to the thin prong and the lead looks to be a little overfilled for the period. The verdigris doesn't take very long to develop, in fact I have a basement that turns my reenactment buckles, where the leather attaches green, over the winter.
Where did you buy it and is there a return policy? Post more pictures when you receive and it will be easier to make a more definitive conclusion. The prong should be thicker and more rounded with a slight upward turn 3/4s of the way to the end.
I have seen arrow hooks beveled that way on originals and I have seen (rarely) a thin prong, but they almost always have the upward bend.