All of the EX90 Series III horns I've seen have been either completely manufactured and assembled by Amati
or all the parts were made by Keilwerth and Amati assembled the horns.

Note that these horns do not have Keilwerth serial numbers.
  • Bb Tenor 353764 Bb Tenor 353764
  • Bb Tenor serial # ? Bb Tenor serial # ?
  • Bb Tenor Bb Tenor 362220 (Probably Amati) Bb Tenor Bb Tenor 362220 (Probably Amati)