Many thanks for the offer, but it's been sorted for a while now! New box carried out as hand luggage with another mate. Got to make it look light at checkin! Turned out mainshaft (or was it layshaft, can't remember now) BROKE. So much for the replacement output shaft and bearings fitted in Yaounde 4 months earlier.
I'm a LR mechanic in UK so I've plenty of places to get a box here. The tricky bit was getting it to Addis Ababa without paying horrendous duties and shipping costs.
Moral of the story: Check the output splines before you go!