AFRICAN BOWIE KNIFE ?

[Royston]

A recent aquisition which came in with some Khukri's.

Not seen anything like this before.
Silver and ivory pommel.
Brass crossguard
Blade looks like an American " Case " combat knife, but is much thicker than the couple that I have seen.
Scabbard is decorated rawhide
Belt appears to be of local manufacture as does the brass buckle.

Any suggestions as to origin ??

Thanks
Roy