These are great little workhorses.
The air cooled engine is only an advantage as you don't have water pumps, radiators and hoses to worry about. Just make sure you take the air duct out and clean the fins very nice as this is usually overlooked by the owners. The air cooled engines also will start pretty much every time regardless of the outside temperatures as long as there is fuel and a battery to turn it over.
These tractors have 4 wheel drive permanently engaged and I see mismatched tires which can be problematic, so be aware of that and also make sure the 4 wheel drive is working.
That is the articulated model, so check for play on the pivot point in the middle, because people fail to grease it properly. There is also two drive shafts running through the middle, make sure both are in good condition.
Looks like you're somewhere located in Europe, which means you're probably won't care for a front loader but if you are looking for a loader tractor, this is definitely not the tractor for a loader.
Again, these are great tractors, climb mountains like a goat and will pull a lot. The PTO has two or more speeds if I remember correctly. One of the speeds is synchronized with the rear differential and it's used to power trailers.