Directories shared by old and new HUD:

  Instruments/


Directories used by the old HUD only:

  Instruments/Minimal/
  Instruments/Custom/
  Instruments/Default/
  Instruments/Engineering/
  Minimal/
  Custom/
  Default/
  Engineering/


Directories and files used by the new HUD only:

  Instruments/*.xml
  Sets/
  *.xml