This was listed on ebay and is still not sold. Tesla : Model S Signature 4-door Sedan in Tesla | eBay Motors A SCAM? Can it be possible that the seller does not know what Signature means?
It looks to me like the eBayer was just confused and it's not necessarily a scam. The auction is closed now which could mean they sold it locally or are going to re-list it as a non-Sig. FWIW, they did update the auction with this: