The 16th century matchlocks were of the type fired off the cheek. Generally short, but with thick stocks. Many have a fluted grip rail ahead of the lock running along the forearm. Almost every one uses the snapping lock - in particular the type with the trigger button right on the lock. There are some listed with bronze barrels. Also, most are fitted with complex sight apertures. About 15 years back there was a good series about the conquest of the Aztecs. In this they demonstrated the weapons of the Spanish as well as those of the Aztecs. In this a perfect copy of a late 15th century snapping matchlock was used. They spent a fair amount of time showing it be loaded, fired, and tested against Aztec shields and other native weapons. The gun was so well made I believe it may have been the work of Dale Shinn. If time allows, I will scan pics of the guns I've mention in this post. G.S.