Rudi Roth is a Swiss born artillery draftsman and scholar now residing in England, and if you've ever looked at any books or internet sites dealing with European and British black powder artillery, then you have likely seen some of his drawings. These are drawings for sale, so of course you can't save and enlarge them, and they also have a large number acsoss the image, but you can still make out the pieces. If you happen to be looking for artillery from a certain country and period, then I've found that this can serve as a quick reference.
http://cannons.ch/verkaufe.htm
