Mark Crudgington, the son of the Crudgington who was co-author with David Baker, owns the rights to George Gibbs. I don't know how good the records are. I have his e-mail address somewhere if you want it. Maybe that F302 is a patent use number. The first pattens for the Gibbs and Pitt were an ugly looking under lever cocking design; I have one with patent use number 37. The more commonly encountered, and better looking, is the sidelock type like yours. I have seen side lever cocking models but very strong thumbs are required to get the neccessary cocking leverage. That will be a nice little gun in 20 bore. Lagopus.....