Complex sentence: In 1963 it acquired ownership of its main supplier of student saxophones, the Buescher Band Instrument Company, distributing instruments under both Bundy and Buescher brands until Selmer replaced the Buescher design in the late 1970s.
Split into simpler sentences: In 1963 it acquired ownership of its main supplier of student saxophones, the Buescher Band Instrument Company. Selmer continued distributing instruments of the old Buescher design under both the Bundy and Buescher brands until Selmer replaced it in the late 1970s.