A Holton Colletiate mellophone tuned in Eb / F. made 1941, but has only been used very little.
  For some reason it has lost a valve trough time, and a new valve had to be built up.
  What is the difference between a melophone and a french horn? A mellophone is played with the
  right hand, and constructed smaller, for use with marching orchestras. The bore is
  cylindrical, making it sound trumpet like. A french horn has a conical bore.
  Mellophones are most seen in American military orchestras, they are less common in Europe.
  Tuning between Es /F is done by changing the tuning slide. Playing in Es, the valve slides must
  be drawn to a mark.
  
Building up a new valve.
Other informations
Made by: Holton, Wisconsin, U.S.A
Made in: 1941
Materials: Brass, matt silver plate.
Condition: Ready for use