That part # exists in the OEM VOLVO 850 front suspension paper service manual (probably not parts literature, don't know about Vadis on that).

I'll look it up for you tomorrow and post it here unless someone else beats me to it.

It's actually the bottom bolt hole that's elongated. A dealer Volvo tech who's done several 850 alignments over the years should know that too. It's not a common operation (havent actually needed to do it in years by us) but IF the front camber is out of specs and there's no obvious bent parts, that's the proceedure and it works well.