I just looked through my copy of "Yahi Archery" and this arrow doesn't resemble any of Ishi's displayed there or described. The metal foreshaft is not typical either. Pope writes here that Ishi's arrows were 29"-30" in overall length. The fletching is much different as well. At first glance I'd ssuggest it was from elsewhere.
Styles never met Ishi and the only reason I can envision he would have placed his name on the arrow, would simply to identify it as his property. Some of the old archers collected stuff as well, and artifacts and specimens from other parts of the country are found in their possessions.
And, it is not uncommon in the collection business for others to place the name of old archers to, let's say, possible increase the value of the item. I'm not suggesting that here, just information as to "why" C.H. Styles may be printed or written on the arrow.
And yes, I have an original "Yahi Archery."