Going to contact the S&W historical guys about this one. Looks like a 1917 chambered in .45 acp. Real nice shape clean inside and out functions perfect. Has a Brazilian Forces mark in 1937. Lanyard ring has been removed and custom grips added. I have the correct grips and lanyard ring on order so I can get it back to original condition and a hand full of moon clips. Appears to have been refinished by the Armory before returning to USA.