Thanks for posting the additional pics! (I was slow with my reply... 

 )
	Quote:
	
	
		| Close up of details of #3: Wrangka, inlaid front and plain back
 Buntut, inlaid front and plain back
 | 
	
 The plain backsides do look carabao to me. The front sides don't come out very well but are mottled and seem to have a different surface structure: could be tortoise, indeed.
Regards,
Kai