Can posts be republished? (same URL, float to top, added to RSS)

We have a few evergreen posts that we want to republish every year, such as some Christmas themed posts. We’d like to see these at the top of our blog just like new posts, and send them out in our RSS feed.

We could just copy the content into a new post. Problems: the same content appears twice in our blog (and in Google).

We could delete the old post and post it as a new post: Problems: links are broken, the permalink changes, the history of when the post was originally published is lost.

Is there a better way?

For instance, what happens if you change the publication data and Save? or Publish?

Or is there some edit we could do directly to our MySQL database?

TIAS (try it and see) is not an attractive option, because we feed to Google News, Kindle, Topix, Moreover, etc., and we don’t want to send them a bunch of garbage tests, for fear of antagonizing them and risking our status with them.