On the note of the CDL lever, if the previous owner(s) didn't use the vehicle much off-road, then the lever will most likely be basically seized. While it may be necessary to re-grease all of the linkages, most people have pretty good luck by just working the lever back and forth over time using some pretty good force. When I purchased my 95' disco the lever wouldn't budge at all, now the CDL engages and disengages with ease, and it shifts into low range super smoothly when done right.
On the note of "random" parts breaking, I don't believe that the Rover has any more chance of "random" parts breaking on it then other brands, however the weak-points on the truck (All truck have weak points) are different then others.
Some of the weak points to look-out for are:
- Drive shafts, they need to be greased every oil change (3,000-5,000) as a rule. If not they will quickly deteriorate and can cause far far larger issues. Check for play in all the universal joints and the slip joint on the front shaft
- Axle half shafts. As long as you are running stock tire sizes or being a sensible driver, the axle half shafts shouldn't prove to be an issue, but they are the weakest point in the gear train. Luckily the D1 has fully floating axles, so swapping HD axles in is a piece of cake.
- ABS sensors, these are known to back out pretty commonly setting off the ABS light, just tap them back in gently.
- Idle Air Control Valve, this can gunk up pretty well and cause some rough idle issues for your rover. (Thanks, @pl626 for helping me out with this one)
- The vacuum retard line for the distributor can easily come off, and most people will not notice it, however it will decrease your horse power and MPG, it cost me $2.50 to get the right parts at my local store to get it plumbed back in properly
- The Rover V8's are reasonably sensitive to timing and overheating. While the 4.0 isn't to terrible, it can still over heat considering the age (Blocked radiator, thermostat, water pump, expansion tank cap, name it). If the rover is over heating DO NOT DRIVE IT. It is so easy to basically destroy one of these V8's by running it hot for any length of time.
- On the note above, the temperature gauge is pretty slow to respond, and will jump suddenly, so get in the habit of checking it.
You have an awesome rig on your hands, best of luck.