I have photocopies of all passport applications made by SULTANAs between 1915 and 1919, including photographs. When did your ancestors move to Algeria? What was your great grandfather's name?
I also have my Family Tree going back to 1629. If you can supply more details I wil see whether I can connect you. Most Sultanas come from either Xaghra or Nadur (both in Gozo) before settling in Malta.
My e-mail address is email@example.com