My only idea for claiming ownership would be to take advantage of this last day online… If you were to email Kevin a story that you were going to post, waited an hour, then posted the message, then Kevin would have a fairly strong indication, based on timestamp or something, that a given email address is tied to a given ficlets screen name.
But it may be too late to organize such a thing.
Actually, now that I look at it, I don’t see timestamps, just datestamps, so it would have taken at least two days to make happen.