As others have said the Morocco/Algeria border is probably closed but you can get a ferry Marseilles to Tunis then your chosen route from there.
Just a thought, what type of Landrover? something with an old fashioned engine might be best down there, not a td5 or anything with electronic engine management, they can't fix it.
Regarding Libya you need a guide to travel with you, I forget who we used but there will be advice on this elsewhere on this site, also posts about getting your Ethiopian visa in your home country before departure.
If gaffer tape doesn't fix it then you haven't used enough tape