Besson Fridays at Home, Episode 2 | Besson Brass

[@danieloleary1782]

I am having difficulty finding an answer to what should be a simple question. What defines an A model Besson Cornet from other models ? How might an A model differ from other models regards bore size , quality, etc.? As I write I am awaiting delivery of a silver plated london made A model Bd Cornet with an A key lead pipe included. Apparently manufactured in the mid 40's, serial number 133522.