I have a Dukoff D chamber perfected by Ed Zentera with a 0.101 opening that makes my B&S 2001 (same as your Guardala) scream really loud. For some reasons the B&S is the most responsive to that mouthpiece, my other tenors don't get as loud with it. I also have a Brilhart vintage Levelaire and there is no comparison in terms of power.
I'd give it for 175$ plus shipping and eventually paypal fees.
I'd give it for 175$ plus shipping and eventually paypal fees.
