Hi I have no info on mauri, but i have sold several cars in senegal and mali.
Tha problem for a 4X4 in Senegal is now the custom papers. In mali it is possible to sell ( if you dont mind hanging around for several days) but of course, since the selling problems in Senegal, many more people are going to Bamako to sell. A good contact is at KATI a few klms before Bamako,if you take the old road thru kati to bamako on the south side of kati (on the right hand side) is a garage/scrap yard/car wash, who has found buyers for 3 times for me. Also i have sold a car and a4X4 whilst staying at the Hotel relais du campagnard , route de Koulikoro Bamako. Good luck