Looks like Geneva recently released a baritone horn for their Oldroyd Cardinal range:

https://genevainstruments.com/oldroy...b-euphonium-2/

Interesting design, non-compensating 3 valve, with a unique main tuning slide trigger activated by a piston where a 4th valve would be located on a normal 3+1 setup.

I'd be keen to hear how it plays!