did you already find http://fr.wikipedia.org/wiki/Liste_des_monuments_et_sites_historiques_au_S%C3%A9n%C3%A9gal ? The list looks good, I'm just a little uncertain how practical the numbering system is (it includes the city name). Also it will require some rewriting to a template system instead of a wikitable (all doable). You could probably dig into the article history to find some interested people. 

It seems Senegal is one of the few countries where our international partners do not have connections (as far as we currently know), so I'm afraid that I'm unable to help there. 

The French chapter might have more insight in who is active and interested locally, but I'm unsure if that is information they will send over a public mailing list - you may want to approach them as well off-list. 

Best,

Lodewijk