I have to second Jens' comments. Here are links to Information on the copper types mainly. They give a lot of incite.
http://www.penn.museum/documents/pu.../Metallurgy.pdf
http://www.fenimoreartmuseum.org/fi...it1/e10554a.htm
Jim, I should mentioned that it's 23 5/8 inches long, probably a war dagger, so i don't know how they were worn. You're right about the neck sheaths for the smaller ones. The hide sheaths incorporated copper on the ends to give the needed protection. You must have an enormous library. I need time to go thru all the very much appreciated information, Thanks