One did (fairly) recently sell at Dix Noonan Webb in London... 26th Sept 07, Lot 591. Realised £1000 plus premium against an estimate of £400-£500 (http://www.dnw.co.uk/coins/auctionarchive/searchcataloguearchive/itemdetail.lasso?itemid=86784) Thats the only one I've heard of, and it didnt come with any paperwork. I believe it was cased, but unfortunately was unable to view it as Mr Webb had it on his person, and wasn't at Bolton Street when I was viewing!