Rollie 1665 caseback on the bay?

[Dizzy]

have a look at this caseback.. do you think its really a gen 1665 caseback and if so.. why the hell would you polish the engravings right off.. AND is it still worth $800?????

http://cgi.ebay.com/Used-Rolex-Sea-...VQQcmdZViewItemQQ_trksidZp1638Q2em118Q2el1247