If you realize you answered a duplicate question, should you move your answer?

Question

I just answered a question and then another SE user pointed out it was a duplicate. Not only was the question asking about almost the same topic, but question body was literally copy/pasted. Usually, I wouldn't support such a question and immediately point out to OP to go read the other one and stop doing such things.

However, in this specific case, I took the time to write a relatively lengthy and maybe even helpful answer. Would be a shame for that answer to go to waste. At the same time, I have an ingrained distaste for copy/pasting, so I don't know if I should repost my answer in the proper place now.

Should I copy the answer over? Should I copy it over and then delete it from duplicate post? Or should I just let it be where it is and move on?

Answer 1

While we can't copy over answers individually, if the question is closed as a duplicate and all the existing answers (including yours) would work without modification on the older question, consider flagging the closed question so we can merge the two questions, which will copy your answer (and all the others) to the older question.

But if your answer, or any of the other answers, need to be modified somewhat, just copy your answer and make any changes necessary to make your answer wholly applicable to the new one.

Answer 2

Three people have upvoted your answer, so it appears useful. Since the two questions are (almost) exact duplicates, your answer should be equally applicable to the original.

If I were in your position I would therefore delete my answer on the duplicate and re-post it on the original, as the duplicate is likely to get closed or even deleted. I would wait though for a moderator to chime in whether such a migration can be done by them in a way that you don't lose those three upvotes.