I ran a 1974 Series III for 12 years . .
The brakes will fill with oil every 500 miles.
The motor will overheat if you tow anything heavy.
If its got the 2286cc petrol motor you won't be bothering 4th gear when towing (I put a 2.5 litre five-bearing crank motor in).
The driving position is cramped.
Very noisy on a long run.
High fuel consumption.
Original leaf springs don't move at all (I fitted Parabolics & Comp Shocks).
Once in 4-wheel drive you have to stop, go into Low Ratio and back again to re-set it to rear wheel drive only.
No Centre Differential so you can only use 4-wheel drive on the slippy stuff.
No CV joints on the front axle, just UJs, so the steering lurches from side to side when in 4-W-D.
I loved it and wish I still had it, it was great around the garden and farm (capstan winch

).
Bob.