Hello,
I don't think that it's such a hard task !
just you need strong planning and trusted contacts
I can tell you that I have worked on 2-3 ferry flights on this route from Europe to East / South Africa, some even flew to S. Africa for pleasure from Ireland and back !
it's not rocket science !
AVGAS is available in Egypt all the year long at 3 Airports !
North Sudan you need the right contacts which I have, they bring the AVGAS from a small city 200 KMs away from KRT from the companies that do crop dusting
South Sudan / Juba, I have contacts who can ship it in barrels from Uganda
Kenya, it's available again with the right contacts
Further south it's easier !
I think it would be a nice adventure , if you are the kind of person who likes to go on adventures, the golden rule, Get the right contacts and always bargain and negotiate on prices !