For my reference, does a world renowned mint strike MS-70 coins off the press? Or is it a mixed bag or MS-68's, 9's and potentially no 70's? Also, what is the check and balances for attributing an MS-70 rating? It seems as though there's such a fine line between 69 and 70, no? What's to stop a collector knowing he's got a coin of superior quality and buy an MS-70 rating over a 69?