This is an E.A. Couturier Baritone in Bb with his patented "Conical Bore" design. Note that the valve crooks are not removeable and are conical from one end to te other. Couturier was known as one of the top cornetists in the US at the end of the 19th century.  He also composed music and ultimately designed a new tubing system for brass instruments. In 1916, he formed a company to make a complete line of his "Conical Bore" Instruments. "Couturier Model" instruments were also made by Conn, Holton and York.  Click here for a detailed biography of E.A Couturier. Please see also my other Couturier instruments: a Cornet, a Trumpet, a Tuba ; a Mellophone; a Slide trombone