The York EEb monster is well thought of even today, and was said to be the bell/body basis of the popular G50 Getzen CC tuba. This particular monster pre-dates the 1910 York patented hi/lo pitch “donut” slide, so this high pitch model makes due with a “W” tuning slide to achieve low pitch. The W shape was to allow for the extra required length, while still keeping the tuning slide out of your lap while playing.

https://simonettitubacollection.com/ins ... -3-piston/