Dear Ed,
We need to compare the actual Fuzzy-Wuzzy knives in XIX century and modern knives.
AFAIK they used straight knives in 1880th onwards.
Then we shood seek for such knives in Museums of Sudan and ajacent countries as European collections could boast only the itrems of the end of XIX century.
And at last we should understand what "shotel" means in Arabic language? Is it a word from classic Arabic language or is it being spread only among Sudanese Arabs?
The Fuzzi-Wuzzy legend seems to be very modern and ethimologistic - to my mind they borrowed the thing alongside with the name and them "explained" the meaning by so called foulk ethimology.
In any case I am glad to talk with you especially after getting acquainted with your notes about Kassala
P.S. could you post the emblem of E.A.C. here?