From https://news.ycombinator.com/newsfaq.html: "If a story has not had significant attention in the last year or so, a small number of reposts is ok." Emphasis added.
From both https://news.ycombinator.com/newsfaq.html and https://news.ycombinator.com/newsguidelines.html: "Please don't delete and repost. Deletion is for things that shouldn't have been submitted in the first place."
From https://news.ycombinator.com/newsguidelines.html: "Please don't use HN primarily for promotion. It's ok to post your own stuff occasionally, but the primary use of the site should be for curiosity."