Jim,
I just now reading "Travels in Nubia" 1819 by Burckhardt. having wadded through the intro. I think Nubia part starts on p.113 after a long intro in Roman numerals. His accounts are the main reference in Robinson's article and maybe there are a few gems therein that he neglected to mention.
https://ia800602.us.archive.org/6/it...ubia00burc.pdf
Ed