See below a report on the complete manufacturing of:
 - a trumpet
- a french horn
- a trombone
- a tuba
Other manufacturers published these videos:
Antoine Courtois :
Bach :
Besson :
Miraphone :
Yamaha :


Mouthpiece manufacturing with a lathe and without numerical tools:

Taylor :


Mouthpieces on a lathe with numerical driving (CNC machining):

Bach :

Denis Wick ( Musicians can feel up to 4µm precision) :