According to Edith Reiter's 2014 book this instrument was completed in May 1950 and originally sold to a buyer in an unknown location.
Howe & Hurd (2004) describe heckelphone #4775 as a model 36k.
As of 2020, heckelphone #4775 is part of the collection of the Heimatmuseum Biebrich in Wiesbaden-Biebrich, Germany. In 2004, Howe & Hurd reported this to be an instrument available for rental from Wilhelm Heckel GmbH. If this information is accurate, it is likely that heckelphone #4775 was kept by Heckel until it was transferred to the museum, sometime after 2004.