Mwinyi Mkuu (Muhammed bin Ahmed al Alawi, 1785-1865) was the last of the line of Shaziri rulers in Zanzibar.  
Mkuu was a Tanzanian term for hereditary ruler.  
 
The Shazadas were dynastic rulers of Persian origin so this dynasty appears to be from Persian settlers there c. 10th c. + 
 
From the illustration the sword referred to has the familiar peak at the pommel seen on 'Zanzibar' versions of 'nimcha'......however the crossguard is notably that of a Persian shamshir. The shamshir was a prevalent sword form highly favored as a sword of status here much as many other places in the Dar al Islam, so not surprising. 
 
This illustrated example however Im not sure represents a form of nimcha as much as perhaps IMO a notable combination of both Zanzibar nimcha and Persian guard.
		 
		
		
		
			
		
		
		
		
		
		
		
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