One thing that I need to do is to collect my various gun inventories from 1652 and 1653

Most of the gun inventories that I have that list the weights of individual pieces on each ship are from early 1653. I have at least one, from a notary document, for a hired ship in 1652. I would think that it would be valuable to be able to make some generalizations about the weights of guns, based on whether they are bronze or iron, regular or drakes (possibly with a bell-shaped chamber). The chambered guns seem to have been bronze. One question is if there were any iron drakes or chambered guns.