Wow! That is absolutely Native American style based on the cut of the feathers. I have seen some really good copies over the years so it would really be hard to date or say it was an original looking a the pictures. Is that a bone nock? Also can you tell if it is real sinew or not? Heck I could spend hours asking questions that we may never come up with the answers to. Would be nice to get some carbon dating to know for sure.