Justin-
 My point exactly concerning fakes- see my post under Chinese fakes. They are getting to be very numerous. I find these particularly insulting, because they are such treasured Native American artifacts and considering what we did to them as a people, this is a double wamie...
Rick-
 Excellent point as well. I forgot to mention that angle. I hadn't thought about the sheer scarcity of man-made nails back in those times. I'm told true nail production throughout the western world began around 1801, so this fits.
Greg-
 Interesting point, and I don't know enough about smithing to land an oppinion. Would riviting like this have been around pre-1840 or so, I wonder?  How would the rivit/plug be put in place?