Gold doesn't tone... So I guess this is a gold plated fake that has been worn down?

http://cgi.ebay.com/1907-UK-Gold-Sovereign...8QQcmdZViewItem

Pure gold doesn't tone, but coin gold contains alloys to harden it somewhat (usually copper) and the copper alloy can tone.

I don't know if the coin in the link is real or not, but I wouldn't condemn it on the basis of being toned.

Gold alloys can come from whitish to reddish hue depending to the alloy content.

True an alloy can tone, but I can't imagine that the 8.3% copper in one of these gold sovereigns (they're 91.7% gold) would cause much if any toning. Especially a dull, greenish color like that.

He has a return policy so at least he seems genuine in that regard.

He put up another sovereign, with the same thumbnail pic, but two new pics in the description. The new pics look legit, although they are much, much smaller.