Can I put a 42 rim on a 43 underpart?
You can physically screw any Reeves or Purviance rim on any Reeves or Purviance underpart but there may be a mis-match from the rim to the cup.(Dynamic Mass Mouthpieces have a different thread so you cant put a Dynamic Mass rim on a conventional Reeves or Purviance mouthpiece). Think of Tupperware: If you try to put a 6 inch lid on an 8 inch bowl or vice versa there will be a mis-match. The difference as far as mouthpieces is concerned is usually very small. If you don’t feel the mis-match with your lips it will not affect the sound or playability of the mouthpiece.
