Bach Vintage Vincent Bach Corp Mt Vernon NY 11 Small Shank Trombone Mouthpiece 1953-1964

This is a highly sought-after, vintage mouthpiece originally handcrafted during Vincent Bach's manufacturing period in Mt. Vernon, New York (1953–1965). 
As you'll see in the pictures, it is in excellent condition for its vintage and has been my primary mouthpiece for several years. 
If you've never played one, my experience is that it feels a little smaller than a modern 11, and has a rich, buttery tone especially compared to the 11c.
I'm selling it because I've decided I want to go back to a larger mouthpiece.
Message me if you want additional pictures or information!