If you are interested in more historical information about Vincent Bach and his instruments these are good references.
ITG (International Trumpet Guild)
ITG Oct. 1976/4
A tribute to Vincent Bach [Selmer Co.]
ITG Dec. 1994/12
The Life and Work of Vincent Bach 1890-1976: The Early Years to World War II. [Smith]
ITG Feb. 1995/4
The Life and Work of Vincent Bach 1890-1976: 1941-1976 and Beyond. [Smith]
Vincent Bach’s World (formerly Bachology)
A series of excellent references on early Bach instruments by Roy Hempley and Doug Lehrer.