Likely refers to Reginald Engelbach (1888-1946) who worked on these particular excavations with Petrie. During WWI, he served with the Artists Rifles, and subsequently was sent by Edmund Allenby, the leader of Egyptian Expeditionary Force, to report on archaeological sites in Syria and Palestine. He returned to excavating with Petrie in 1919-20 at both Lahun and Gurob and subsequently had a stellar career in the Egyptian Antiquities Service, first as Chief Inspector in Upper Egypt in 1920, then as Assistan Keeper at the Cairo Museum in 1924; and finally as Chief Keeper in 1931. 

Some of his papers are in the Griffith Insitute at the University of Oxford but some were sold at auction at Bonhams, London, 23 June 2009, lot 110.