Anyone that knows if it is possible to download a manual for the 850?

Haynes did a manual so abebooks or eBay May score a cheap copy

I have a couple of aftermarket manuals. One is by InterEurope workshop manual 198. This is pretty good and you do see it on eBay occasionally. The other one is by AutoBooks. Autobook 765. This is a bit better and shares the same pictures as the other but has more detail. Caution though with some of the torque tensions quoted in these manuals, they may vary a bit from factory recommendations.