Shotgun identification any help ??

Jack Cl, The letters AP within a square is the Gardone Proof house date code for 1986. The maker's mark is located below and to the left of the date code on the bottom of the monobloc. Can you highlight the maker's mark with chalk or other substance that will better show the details of the mark? There is also a mark of some sort in front of the serial number on the top tang (under the top lever) that these old eyes find difficult to read. Can you highlight that also? What, if any, names/addresses appear on the barrels or vent rib? The "CAM 70" refers to the chamber length of 70mm = 2-3/4". FWIW, The gun has a typical "Brescia" action used by numerous Italian makers during the 1960's - 1980's. It is not a Kersten lock but, rather employs dual "hidden" Purdey extensions which nest into slots in the standing breech and are locked by a sliding flat crossbolt. When the action is closed, the extensions are not visible. A true Kersten system has visible slots at the top of the standing breech allowing the top of the Kersten extensions to be seen when the action is closed.(Google Hallowell Fine Guns/Illustrated Firearms Dictionary/ Kersten Lock) and employs a round crossbolt. The Japanese SKB O/U used a modified Kersten lock employing a flat crossbolt. The stock style and barrel length loudly proclaim "field gun" not Trapgun. The 18.4 mm stamped on the top and bottom barrels indicate a .005" choke constriction from the "standard" .729" of that era which approximates a skeet choke. Many Italian guns of that era used stars to indicate choke: * = Full, ** = IM, * = M, ** = IC. The single trigger appears to be a non-selective type. Be aware that during the 113 years since the founding of the Gardone Proof House, over 600 different gunmakers have registered their maker's marks. The vast majority of those firms no longer exist. The maker of your gun may be amongst them. DF Montani Semper Liberi