https://www.bcu.ac.uk/conservatoire/research/hic/the-collection/mouthpieces/13-2
Trumpet, Cornopean or Keyed Bugle Mouthpiece - Historical Instrument Collection | Birmingham City...
Birmingham City University (BCU) is a large and diverse university set in the heart of Birmingham with a focus on practice-based learning.
keyed bugletrumpetcornopean