Mike, I'm not the most knowledgeable when it comes to bows, but when you wrote, "May have been nothing more than to protect the ends and notches until time to sting the bow. Not sure."..... I got to thinking that what you may have seen was the "stringer" it self.
I keep my "stringer", with its two little leather pockets that cover the end/ tip of the bow, on my bows when they're not in use, just so I don't loose it.....not that I use it all time.
I've grown lazy in my old days, and a lot of times I just use the "step-thru" method to string a bow.
It's just a guess on my part, but that is about all I could imagine you might have seen when it comes to leather on the tips.