Bill, that's one hell of a sword ! Yep....now you got me jealous
I found a similar sword in the book 'Afrikanische Waffen' by Werner Fischer and Manfred A. Zirngibl (1978). It's almost similar to yours.
The shells on the sheath belong to the spondylus-family. They are naturally red, but are polished in order to give them a smooth surface before using them as a decorative addition.
Here's the pic from their book :