Hi,
Thanks for the response.
This horn has a under-slung third valve slide ring, you can verify its in the correct potion by noting the spit release valve being in the correct direction on the same slide.
The horn is in stellar condition, the valves are smooth and quiet, all slides are easily movable, and the body has nearly no damage. Its sound it full and pleasant.
I haven't been able to locate any information about this cornets origins.