I have the following up on ebay. 17c Vincent Bach cornet Mouthpiece. VINCENT BACH CORP. 17C Cornet Mouthpiece RARE Small Letters “VINCENT BACH CORP. 17C” Ideal for Soprano Cornets. Below is what I was told when I received this. You are bidding on an essentially new mouthpiece. This item sat in a drawer for nearly 30 years or more. I cannot see any insertion marks on it, there is just tarnish. It likely was tried out once or twice. It comes in an old style Bach mouthpiece box. I have now cleaned the mouthpiece up and it looks superb.