I recently came into possession of what I believe is, according to the York Loyalist, a Model 27 Eb Alto Horn used between 1915 and 1921. It has an 8 ¼ inch upright bell. It is the bell size that distinguishes this instrument from others on the list. It is 10" long. I don’t see any markings on it to show me if it is low or high pitch but I believe it is low pitch. The mouthpiece that came with it reads “Conn-Euphonium”. It has a small shank and looks like a “smallish” baritone mouthpiece.
The thing that is confusing to me is the extra bit of tubing beside the third valve slide. I can’t find any picture of any instrument that has this particular additional tubing or any details on what it is. I’m attaching pics of the instrument.
Thanks in advance for any additional info you can provide!