A rather specific question... I've got a 1918 York Model 33 Bb tuba, and I keep reading how York tubas have large mouthpiece receivers, but mine has a diameter of 14 mm (0.55 inches). "Standard" tuba mouthpieces barely go in, and since the horn already plays a bit flat, they just make things worse ...

Many thanks for all of the tips. It seems it is indeed a tenor horn. As for the age, my earlier estimate of 1905 seems about right, though it may be older than that. Any leads on reliable Cerveny serial numbers from that era would be appreciated.

I'm seeking help dating my Cerveny horn. IMG_20230111_141413537.jpg IMG_20221231_135319091.jpg It has a serial number 2195 on the bridge under the keys, Screenshot 2022-12-22 11.48.14 AM.jpg and another number (28648) where the tubing from the mouthpiece attaches to the first valve. IMG_20230101 ...