@user6726 Is either of them here on Linguistics SE? Maybe they know someone… Otherwise, do you know someone who speaks Mende? That could still be useful.
AFAIK no, and I doubt David would be here. I do not know any Mende speakers, or anyone (approachable) doing research on Mende. I don't think Chris would get angry if you sent him an email out of the blue (using your Google-foo), but he's not a speaker.