I don't think it's weird. People re-post old fic all the time and the fact that you wrote the fills anon doesn't make it different in my mind (it's no different than re-posting fic written under a different screen name).

You could add a note saying you wrote the fic years ago for a kink meme. I would never assume an author is lying about that and I don't think most people would.

Personally, I'd appreciate it if people put more smut where it's easy to find! ;)