The 1852 catalogue of Mayer's collection describes the mummy as being of a "frequent way of embalming, first enwrapping the body with bandages, and afterwards covering the whole with bitumen". In 1877 the British Museum's first Egyptologist, Dr Samuel Birch, visited the collection to provide advice for the curator, Charles Gatty. Dr Birch said the coffin (M13999) and cartonnage case (M14000) did not belong together. Mr Gatty also noted that Dr Birch “thought very highly of this coffin”. From then until 2008 the mummy of Padiamunnebnesuttauwy (M14050) was, by error, kept inside coffin M13999.
In the British Museum's collection there is a similar cartonnage encased mummy of a priest called Djedkhonsiufankh who in all probability is the father of Ankhesenaset (British Museum number EA 6662, which is also from the Joseph Sams collection).
For a comparison see, Taylor and Strudwick, The Theban Necropolis (London, 2003), p. 108, pl. 52 [coffin of Kharushery, New York, MMA 86.1.31-32].