Talk to theymos first. Send him a PM and check what he has to say. He isn't going to delete a random post and give you the ID for it. He will give you the ID of a post that was already deleted in the past for whatever reason. It worked in my thread, maybe it will in your as well. If theymos can't do it, he will let you know.
Nah, I don't wanna bother him with it, its not that important. I thought that it can maybe be done on mod/admin level but since it can't I'll just sort that out in a different way. Anyway, thanks for suggestion.