Speaking of shipwrecks, one of the most informative sources I've yet found are on actual archaeology sites with surviving examples. These papers are like free down-loadable books with exacting information on the length, construction and origin of patterns. For future historians who are interested in this thread, I wanted to attach 3 such sites with info. The first, based on the dive of the French ship Machault (Fernando, you recently posted a pic on another thread about boarding axes with this ship in context). This article by Douglas Brice is long, but absolutely worth it concerning the differing construction (solid cast, cast balls with full bar, etc)-highly recommended.