Patrice, would love to hear your list of book recommendations for Western Soudan (Mali)
If you can read French, the main source is Gallica (the French National Library online)
http://gallica.bnf.fr/Free downloads. Lots of photos too.
Begin with "Voyage au Soudan Français" (cdt Gallieni).
Or "Les Francais au Niger" (Pietri) for an overall view 1855-1883 and many ethnic details.
Find other books with "Soudan" research.
Have a look at "La Marine au Niger" (lt de vaisseau Caron), on the last page there is the plan of a funny very small gunboat.
Back to topic : there are also lots of pics and books about Algeria on this website.