A late 17th century provincial tumbler cup

A late 17th century provincial tumbler cup, with a slightly flared rim, scratched with initials I over FM, maker's mark AD, struck twice and town mark a cross with a device in each quarter, also struck twice, unascribed, 3in (7.7in) dia, 2oz. See Jackson's Revised, p.370 for marks of this type, attributed to Coventry.