Philly-minted 1940 Mercury dimes are extraordinarily common in all grades through the Gem Mint State levels and, for the most part, pose little challenge to enthusiasts through MS67, both Full Bands and non-FB. Top-notch examples do become scarcer, but even in MS68FB this piece has several dozen known survivors, so picking a quality coin should be little problem for those who are willing to pay a small but worthwhile premium.