Hi, im finding whats online about these hallmarks confusing, can anyone help me understand them please? , also the Arabic inscription…or the name of a photo-translate app that isnt useless ! Thanks in advance 
The inscription im told reads Cairo International Fair on the top line, Economic - centre line, and 79 something something Construction at the bottom.
Hoping someone can not only fill in the blanks,but also give me the context, as i know enough of Arabic to know thats necessary. Any help would be much appreciated!