Saudi Arabia, Hejaz, SG D57-D59, MOG.  1924 Postage Dues, with 1988 FILATCO Certificate signed by David Graham that states:

Genuine Khilafa overprint in gold on Postage Dues of 1923, ½pi. Pos. #1; 1pi. Pos. #3, & 2pi.  All are survivors of a fire in a Hejazi stamp dealer store.  All genuine copies are charred darkish in appearance. Some interleaving stuck to gum side.

Perforation faults as always.  A nice looking set that is missing from even advanced collections.  Rare.  2008 Stanley Gibbons CV: £11,250.00