[Conogre]

Here's a photo of me with the shield for perspective...excuse the quality of the photo, but Murphy's Law is in full effect again, with an overcast, rainy day BUT I have someone to take the photo (if this breaks anyone's monitor, my apologies beforehand! **grin**)
The shield seems to be a large sparring shield of the type used against spears, knives and thrown projectiles, relying on the user's speed and maneuverability to knock aside the threat, just heavy enough for protection while still light enough for quickness.
Viewed in this light, it's actually perfectly shaped and just the right size, muc harder to achieve than one would suspect.
Your comment about the Cameroon aspect may well be dead on as well, always a possibility with Africa's often fluid population moves according to the political pressures of the moment and tendencies towards tribal genocide.
Ranges often varied by surprisingly large areas over very short periods of time, always a major problem in relation to tribes and geography.
Mike