Interesting pictures. Our interests are similar(I am an archaeologist)so you may find my article on nail manufacture and chronology useful. It was first published as "Nail Chronology: The use of Technologically Derived Features," in Historical Archaeology (1998, 32(2):78-99). The article was reprinted in APPROACHES TO MATERIAL CULTURE, Research for Historical Archaeologists, 2nd edition, Compiled by David R. Brauner, published in 2000.