A very interesting discussion, may I pursue it a bit farther?  I have 
searched patent art, earlier for a living, now for musical insts, and  recalled that 
the USPTO classification system has a "Measuring and Testing"  Class 
33/subclasses for such inventions.  Taking a quick look/search of our  subject via 
"clarinet AND measuring AND mouthpiece AND interior" , I found two  pats to 
Lorenzini US 4,219,937 and 4,485,559 [both expired] related to his  work?? on bore 
and mp measurement, which may interest several of  us.  I may "dig a bit 
deeper" and welcome others to do it also [will  help].  "Nuff for now, Don



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