Remington 51 Type I, .380 auto cal. automatic pistol.  Serial #PA7991, mfg. 1918-21.  Very good condition.  3” barrel has very good shiny bore.  Slide and receiver have 50% original finish turning patina with some areas of light corrosion and muzzle wear.  Early Type I slide with 9 serrations and no caliber marking.  Remington-UMC grips are excellent.  Correct magazine.  Action works fine which is a plus. A nice early version of this famous automatic!  C&R OK.