When I started the DB years ago, I went looking for every York horn I could find. That was about 200.
The Tuba Exchange's horns were part of that.
I had to accept that they knew that the horn was "York & Sons" even though there was no bell.
Looks like that was a bad assumption that I've been carrying forward all this time.
Years later I now have about 4,000 horns and many know dates to recreate to serial number list from.
As you say, looking at now known "York_ Artists", its clear that this is one of the Carl Fisher overlaps from 1941-1971. Here is a known horn to compare from Horn-u-copia:
So it does seem to be a York, but hardly a "York & Sons" from 1910.
I've corrected the database.
But PLEASE keep looking over my shoulder. I do this in my "spare" time and can use the help!