As far as I can tell there were/are three full siblings from this breeding of the full brother and sister Zaber and An Saaf by Prof. Stumme. The three are:-
Sallah a grey colt foaled in 1982
Bint An Saaf a grey mare foaled in 1983
Asia a grey filly foaled in 1984
According to the AHA Datasource none of the three have any offspring, but this may not be absolutely correct. Very interesting breeding though!
An Saaf also had 3 daughters by Kaisoon and 1 by Jamil who are
Aroussa grey mare 1978 by Kaisoon (no offspring)
Aziza grey mare 1979 by Kaisoon who had one daughter Aicha 1983 by Messaoud. Aicha has no recorded offspring
Amira grey mare 1980 exported to the USA where she had 1 daughter Anamala by Shaikh Al Badi who has bred on with 2 get & 7 grandget
Aja grey mare 1984 by Jamil (no offspring)
Hope this Helps!