Ovangkol is/was a sustainable experimental rosewood replacement in the acoustic guitar world. It's tropical, African, and hard as a rock. Taylor, C.F. Martin & Co. etc. tried it for a while. Opinions on its tonal properties vary widely among guitar players, but I played a Martin OM Custom once with sides and back made of Ovangkol I thought was fantastic. I can't say it was that attractive though...
That's a pretty cut of it. I don't recall seeing another Alembic made of it. I wonder if the customer supplied the wood for the build, or if Alembic was ahead of the curve in trying Ovangkol? (it was later on in the 90's that stuff hit a peak in popular use, as I recall)
*Interesting: The Wood Database classes Ovangkol with Schedua.
https://www.wood-database.com/ovangkol/