Firstly how bad are the cuts and where are they on the tyre ? also how old is the tyre and how much tread is left on it ?
Are they on the sidewall or tread and how long are they ? - if it is sidewall then yes maybe worth finding a new one - if they are not too long and on the tread, patch them, plug them, keep it as a spare and run it only on the rear of the vehicle.
I would have suggested Nouakchott to try and find a Michelin - but a bit too far North- I doubt you will find an XZL though in the size you require -Mainly only trucks use them in WA.
My suggestions would be:
1) Patch it up and keep as spare as mentioned.
2) to find a Bridgestone equivilant - Dueler MT 673
Bridgestone are much better represented in WA than Michelin, if you cant find what you are looking for from the locals then try:
They MIGHT be able to help you out - and you could ask them if you could pick it up in Accra if it needs to be ordered.
2) failing that just keep an eye out for another 4x4 with a similar tyre and ask him where he got it - or buy it off him.
3) depending on how much you want an XZL - contact the Michelin dealer in Algeceras or Morocco and ask him to ship you one - rather expensive though.
Hope this helps