Hi Justin,
Half stock English fowlers probably go back to the 1750s or perhaps earlier but they were not the norm until the third quarter of the 18th century. Also, some, even high end, full stocked fowlers were turned into half stocks during their useful life so it sometimes can be difficult to judge if an existing half stocked antique was originally full stocked. The style of the wire work on Silver's gun is representative of work done before the 1770s so his gun should represent something made when half stocks were uncommon. As with so many innovations, William Bailes was credited with introducing the metal under rib on half stocked English sporting guns during the 1760s. William Bailes was incredible and is one of my gun making heroes. My other major hero is Heironymous Borstorffer. Can you imagine attending a party and someone asking who influenced you the most, and you respond William Bailes and Heironymous Borstorffer. What a nerd!!!
dave