According to Edith Reiter's 2014 book, this instrument was completed on 4 April 1909 and sold to a customer in Italy.
Howe & Hurd (2004) describe heckelphone #45 as a model 36b; however, it is special design with an upward curved bell - the only of its kind.
As of 2020, this instrument is part of the collection of the Grassi Museum für Musikinstrumente in Leipzig, Germany, where it has been assigned inventory number 1353.
The history of heckelphone #45 remains mostly unclear.
A picture of and detailed information about heckelphone #45 can be found here.