Well, from what I can tell, it looks like walnut. I'd say its about 1/32 inch thick, or 2mm. The same thickness as one layer of the headstock laminate on a neck through bass or the same as the walnut neck veneer on a set neck bass like the Orion. Subtle detail, intended as function, but enhanced beauty- As someone famous once said, Nice to ogle at during boring guitar solos. ;-)
I guess removing it from construction is a bit like breaking /tradition/.
Bryant