LH2,
sorry, no first hand info. I haven't managed to fly to these countries ... yet.
Tunis: based on my own pre-planning and on comments from others, quite straight forward with no particular issues. Avgas is not always available at other airports, except at the capital.
Lybia: tried organizing a 5 ship flight last year. Abandoned the attempt due to not obtaining the authorizations and no confirmation of fuel availability at all airports. I don't know if they require a local pilot on board if you intend heading inland.
Algeria: never received an answer to queries sent to the authorities.
Let us know how it goes.