Used Holton Hybrid Alto Sax Mouthpiece
This is an interesting mouthpiece that I hadn't seen before. I believe it's made of Bakelite (hard rubber) with a metal core. I gave it a quick test play and it worked, but it has a very small tip opening, which was common at the time it would've been made. The backbore is also very small and didn't fit on modern saxes with a ring on the end of the neck. I got it to fit on an old selmer but just barely. The cork would need to be much thinner to have it fit properly.