140K 300tdi - deep desert - what would you do?

Hello all, this is my first post here.

I'm prepping a 96' 110 for a long desert trip this winter. We will be in remote areas a long way from mechanical help. Reliability is crucial with the vehicle itself (and potentially worse) at stake if anything goes wrong.

The TDI's about to clock up it's 140,000th mile and I'm totting up a list of precautionary jobs that would be wise to carry out before leaving. I'm wondering what people here would do if they were in the same position?

My main worries are the engine and transmission.
On cursory inspection, the following problems are visible now:
A good cloud of black smoke on start up (goes when running)
some leakage around the injectors
transfer box very oil-wet
worsening 'clunk-of-death'
oil leakage at rear diff/UJ mating

Opinions gratefully received!!

We do desert driving in Australia and leave our Landrover at home and use our Landcruiser which is setup for desert driving with water and long range fuel tanks.

If you use the Landrover, make use you do the obvious, take plenty of fuel and water as well as 2 or more spare tyres.

Also take an EPIRB and flares and if you can afford it, a satellite phone or HF radio. The flares are for if you set the EPIRB off and an aircraft come looking, set a flare off for them to help find you. EPIRB's save several lives a year in the Australian deserts.

I'm more interested in specific reliability probs with the 300tdi engine + transmission at this mileage (140K). Thanks anyway!