Now that you've bought it you MUST do the following:
1) Ensure that it is a serviceable shaft, including the centering ball. Do NOT delay. A blown shaft will take out your tranny. Use high temp grease (usually the red-stuff).
This is the fitting for your centering ball:
https://www.amazon.com/gp/product/B0002SR6XE/ref=oh_aui_search_detailpage?ie=UTF8&psc=1
2). Buy an ultraguage and mount it permanently. My D2 had full records too, with the HG recently done by one of Utah's best Rover shops. The temp. guage was on center. I drove it for 2-3k miles this way. One summer at the McDonald's parking lot I realized the guage moved slightly off-center. I got the UG on the way and installed it and found out my temps were pushing 250F on a mild incline at highway speeds! What!? My thermostat was clogged. Possibly the cause of the HG failure in the first place. I was driving a time bomb. I bought the 180F thermostat for the TD5 diesel motor and now I don't go above 210F in 4-low climbing hills in triple-digit temps in Moab. It is a MUST buy:
http://www.ultra-gauge.com/ultragauge/index.htm
http://www.roversnorth.com/ProductDesc.aspx?code=PEL500110&type=0
3: Do the rest of the high mileage service as needed, before $$ spent on mods: diff, tranny, T-case fluids. rear flex plate (inspect it for cracking), etc.
It took a bit to sort out my '99 which I bought for $5500 with 94k on the clock. I also paid more than the going rate as GetLost4x4 mentioned originally....a clean one in Utah, with records, commands a value that is not market on KBB or the banks. But it was still cheaper than a Land Cruiser!
Once I got everything sorted out, my D2 has been the most reliable (*knock on British Teak*) used car I've ever bought. I'm now up to 127k miles or so and two successfully uneventful trips to Moab.
Enjoy your D2!