6/21/21 - This is an original "fxo" Luger magazine with two proof eagle/37 stamps on the frame, and an aluminum base. The base is stamped with with a Numeral '2' and serial number '7304'. This would have been a spare magazine for a 41-42 byf luger. Or a police re-issued magazine. The bluing has some typical wear and is in excellent condition. No rust or pitting. Strong spring. Original and fully functional magazine.