Life of a V70 built in 1997

Hello Swedesgemeinschaft, I once had a240 and would now like to put a V70 2.5 combo with 144 hp from 1997, which I have already drawn into the closer selection. The elk has run a proud 343,000 km, has always been cared for by his shepherd, a Volvo employee and has been supplied with original parts and looks still very well maintained. Well my question, but have received such an answer nowhere exactly here. How long do these above-mentioned engines, with continued good care and no racing events last? What about the rust susceptibility and where exactly? Have to give my oldtimer, BMW E28, because the spare parts procurement across Germany will be too much for me. If the view would be only 50,000 then I leave it. Thanks for your help.