On haititrust.org they now have Military operations Togoland and The Cameroons 1914-1916 by F.J. Moberly the British official history and while armor and motor vehicles didn't play much of a role in the campaign they are mentioned see pages:
139 armored truck
159 armored train
164 12 pounder on rail road truck
328 the 581 Mechanical transport Company ASC arrives with 1 armored car 2 ford cars 25 ford vans 4 ford ambulances and 2 Ford first aid vans