This question contains an answer that was deleted by owner. Besides a lack of references I think this answer deserves to be visible, so I am wondering how to proceed to make it visible for all (not just those having 2K+ points).
I am thinking about casting an undelete vote, but this still feels weird since it goes against the author's will.
Question: How to proceed if I think an answer deleted by owner is valuable?
In general I would be very hesitant in undeleting content that was self-deleted, especially if it's self-deleted shortly after posting it.
It would be a different matter if someone starts rage-quitting, deleting content because they're having some argument somewhere, or something like that; but in this case it looks like the author was using the delete feature as a "draft"; they deleted it immediately after posting.
I don't know why they never finished/undeleted it, but I don't think that we (the community) should decide if the content is "good enough" to keep. Perhaps the author felt that it wasn't good enough, or that it was better covered by another answer and that their answer no longer added any value, perhaps they felt they were mistaken, or perhaps there is another good reason.
In this particular case, I happen to know that the author is regularly active on chat, so if you want talk to him about it you can ping him there. In cases where the author isn't on chat you could consider leaving a comment on a recent question or answer of the user, but in general I would only do it in cases where the answer was very good/elaborate, and really worth keeping (in this particular case, I'm not sure it is).
I see nothing there that couldn't be easily recreated in an answer posted by someone else except the author's name.
The text is clear, but probably not worth copying. If you think they are good points expand on them (and provide the links as called for) in your own answer in your own words.
If you feel bad about credit note where your inspiration came from or make it a community wiki, but it is a good looking start to an answer despite not having references because they are ideas that you have seen before.
Don't let an aborted attempt poison the well; if you want the concepts mentioned to be visible you can make them without bothering with a vote. If you do it would be nice to include some links.
