According to Edith Reiter's 2014 book this instrument was completed on 11 October 1987 and originally sold to a buyer in Switzerland.
Howe & Hurd (2004) describe heckelphone #4989 as a model 36 voll cons.
As of 2004, heckelphone #4989 was reported to be located in Biel, Switzerland, owned and played by oboist and heckelphone specialist Alain Girard, who is likely to have acquired the instrument directly from Heckel.