Here is a very poor photo I took during the 2005 visit, included because it does give a slight further idea of the door:
Tomb of Perneb - Main Offering Chamber, false door
Egyptian, Old Kingdom, ca. 2381–2323 BCE
Saqqara; Memphite Region
Limestone, paint; H. 482.2 cm (15 ft. 9 13/16 in.)
Gift of Edward S. Harkness, 1913 (13.183.3)
West wall of the chamber, it is where Perneb's KA receives his offerings
