I have been working this summer on my new Phaeton Flugel. Long story short, it is too long. The entire horn is flat by at least a quarter tone! Yes, the lead pipe is all the way in. Yes, I've tried a few mouthpieces. Is it possible they made it too long? Is it perhaps something caused by the funky bracing? As an experiment I pulled the lead pipe out about an inch and it played beautifully in the key of A (concert).
I have to lip this thing up way too much to be in tune.
Maybe it's time for the hack saw?