A whole new grading challenge! A lot of these must have slipped through as 'clipped' I'm thinking. I'm presuming this is a phenomenon consistent over a number of flans, and they've been on the button, weight wise? Could it be that the engravers were expecting larger flans, but the silver was just coming through too thick? There are 3 decent examples of the 1645 F7. Mine (ex-Lockett 2460), Carlyon-Britton (1921) lot 337 and Morrieson 534. All are well centred, but missing the reverse periphery. Attached is a less desirable example off Lloyd's site, which although off centre on the reverse, is still too big.