The Baker Black Beauty is a sidelock. The "Black Beauty" was the gun the Baker Gun and Forging Company replaced their Batavia Special/Leader/Damascus line with circa 1916. When Baker sold their gun business out to H & D Folsom circa 1919, Folsom reintroduced the name Batavia Leader as a steel barrel gun similar to the old Batavia Special. Folsom added a bit of engraving to the Black Beauty and renamed it the Black Beauty Special. Folson era Bakers have an F before or after the serial number.
Here is a 16-gauge Black Beauty Special Ejector with 30-inch barrels --
