Hi Colin,
I would agree these are from the Sahel, Hausa or Fulani seems likely. Although a similar style is used across the entire region.
I've seen more in bronze from the Hausa.
This link may be of interest, although more related to the Mossi.
http://www.saheldesign.com/2012/05/2...asting-method/
They all seem to follow the same pattern, some with an angled plate for the foot, others flat like yours.
I don't know of much reference material on these, just what I've seen labelled on tribal art sites over the years.