To what extent do these gaps in Wagner’s evidence blunt the persuasive power of The Skull of Alum Bheg?

Historical reference

From the first, scholar Kim A. Wagner freely acknowledges that he has not been able to uncover any historical reference to Alum Bheg outside the handwritten note accompanying his putative skull, let alone verify that said skull belonged to this specific shadowy sepoy.

To what extent do these gaps in Wagner’s evidence blunt the persuasive power of The Skull of Alum Bheg?

In other words, how much of his overall argument rests on pinpointing Bheg’s identity and tying the skull now in Wagner’s possession to that particular individual?