[Dixielandjazz] Mouthpieces (was: Louis Armstrong mouthpiece)

[Bob Smith]

While we're on the subject of mouthpieces:
Has anyone ever designed or tried to design a mouthpiece where the part that 
contacts ones face is not the rounded end of a cylinder?
In my own case,  my upper lip protrudes slightly more than my lower lip. 
This gives me a problem (on the trombone) that when I play the lower Bb and 
A, blowing parallell to the instrument at mf, these two notes often suddenly 
change to a 'burping ' sound. To eliminate this, I tip the instrument down 
for these two notes. However, this reduces the quality of the sound 
somewhat, as I'm not blowing parallell to the instrument.
I feel that a mouthpiece where the part that contacts my lower lip is more 
prominent than the part contacting my upper lip would overcome this problem, 
and wouldn't diminish the quality of the rest of the register.

I've often thought of trying to modify a mouthpiece. Could a plastic 
mouthpiece be modified in this way?

Cheers

Bob Smith