Volvo 850 T5-R – What things to consider when buying?

Good morning together, For a few years I’ve loved the Volvo 850 T5-R of an old friend who bought the car in 1995, it’s a black model, the mileage is about 440,000 if I really remember it. I’ve never had experience with Volvos, I’m on the road in the house Volkswagen, and even then only until 1991, the cars have always done it to me, I was just about to buy a V70 Type S, this However, I was “snapped off”, so it never happened 🙁 To the T5-R: It has been standing for about 7 years, the last of it outdoors. It has a Prins gas system installed, it should be a VSI, once a new valve has already been used, because a cylinder had no compression. My first question would now be whether the long operation on gas could have been a problem for the engine? I would be interested in whether there were large differences to the normal 850s in terms of bodywork, There are axles, brakes and steering, and how generally the spare parts supply is? Where are typical weak points, especially after such a high mileage and service life, to which one should pay attention? The interior equipment is except for the driver’s seat, which is very cracked, for the mileage in a good condition, there was always a small dehumidifier in the trunk. I would like to know more about this model, but the community seems to be very small, so it falls to me s to get to the corresponding information. Dear greetings from the Oberbergischen!