Penzel-Muller Baritone
Penzel-Muller was established in New York City in the 1890, by two German immigrants, and had a long and successful run producing clarinets to compete with the finest imports. The firm seems to have never manufactured brass instruments; those labeled Penzel-Muller were unlabeled imports stamped by the firm. The current example likely was made between 1899 and 1916.
It is in high pitch with a tenor trombone shank; the sound is close to a modern British baritone. Good original condition with tight valves, but little of the original silver plate remains.