also since St Marks only consecrated 1772 unlikely that Wm who married in 1773 would have been baptised there and also since the marriage states he was of Kk German

there is an illeg Wm shimin born to a Wm Shimin(fortie) + Marriot Shimmin in Malew in 1740 (which is abt the date I'd expect for a birth with m in 1773)