According to Edith Reiter's 2014 book this instrument was completed on 5 January 1950 and originally sold to a buyer in the USA.
Howe & Hurd (2004) describe heckelphone #4773 as a model 36k, with split finger touches altered to plateaus by well-known woodwind repairman, Carl Sawicki, of Fredericksburg (TX) in 1985.
As of 2006, heckelphone #4773 is reported to be located in New York (NY), USA, and owned by noted heckelphonist, Mark Perchanok, who used it for several recordings with the Paul Winter Consort as well as for performances with the New York Philharmonic Orchestra. Perchanok acquired the instrument around 1985 from bassonist and woodwind repairman, Carl Sawicki, who at the time had a workshop in New York. Sawicki had purchased heckelphone #4773 from the widow of German-American oboist, musicologist and music publisher, Josef Marx of New York City (NY), who owned it until he passed away in December 1978. It is unclear whether Marx was the first owner of heckelphone #4773.
Heckelphone #4773 can be seen and heard from 1:25 onwards; although Leonhard Bernstein finds it to be a "beautiful thing" and calls its sound "terrific", he appears to be unaware of the difference between a heckelphone and a bass oboe.