Well here is an interesting listing....As I understand it the Countermarks on the coin date to the 1920s......However the base coin is a Brussels/Birmingham mint strike dating to the period 1937- 1957. Perhaps the major error claim is more appropriate than the seller realizes!
http://www.ebay.com/itm/SAUDI-NAJD-...em3a7b8d724fBtw the pricing is extremely optimistic