What do I do about this dodgy Ebay seller?

No, the listing isn't accurate. There's a huge difference between saying 'no lockring' and actually telling the truth, which would be to say 'no lockring, so you'll need to spend at least sixty bells to put it right before you get to ride it."

If I sold a wheel on ebay do I need to tell you that there's no bike included so it would make cycling somewhat difficult? No. The listing is accurate.