For reference, I am looking at this MSE question in particular, which mentions obtaining an answer on MO here. I guess the question was posted to MSE first and, perhaps after nudging from other uses, reposted to MO? I'm not too sure, but I don't think the specifics are too important, since I imagine this question is not unique in this respect.
My question is simply thus: how should we handle such questions?
My go-to response was simply a copy-and-paste of the accepted MO answer, posted as community wiki and with a brief blurb at the top attributing it to the responsible user and explaining that it was posted on MO. Or perhaps it should be flagged for deletion? I'm not sure, so I figured I'd ask.
(Of course I also haven't actually done anything as of yet.)