This is a Triumph Baritone. Serial number is 18xxx.
This instrument is shaped in a "squat" type design, similar to the compact Euphonium, with quite a large bell.
The baritone has been restored, with the valves rebuilt and all dents removed. Photos here show both before and after.
The case appears to be period correct, but may not be original. It was covered in brown vinyl with a green felt interior that had a very strong odour of cigarettes. The vinyl and felt were removed, the timber re-glued and a layer of fibreglass applied to the exterior to provide strength. The exterior has been repainted bright red, with a custom form fit interior created for the inside. The final photos show the final product.
Record indicate this instrument was manufactured on 16th September 1925.
The additional baritone is shown for size/shape comparison, and is a standard student model Yamaha baritone.