Hi, folks! I just bought a 70s King 3b and it came with the previous owners King 11m mouthpiece. I surprising like the piece but am unable to find information about it. Does anyone know the history of these King mouthpieces, such as what the 11m is similar to in today’s market?

Thanks for your help!

You may find this older thread helpful...

https://www.trombonechat.com/viewtopic.php?t=6031