The Beretta is an M1934 military model in 9mm corto or 9mm Browning short or .380 Automatic Colt Pistol (ACP) caliber. The letter "M" could indicate "marine", or naval issue. Gardone V.T. means the city of Gardone, Val Trompia where the Beretta factory is located. I don't recognize the o over T marking.
Your P-38 pistol was manufactured by Mauserwerke in944, as byf was their manufacturing code.
Value will be determined by condition, completeness, and matching numbers. I suggest that you browse Guns America or similar auction sites for comparative values.
HTH
John