i found a david drummond of Edrom married to a Clazie and several more Clazies in the Borders but
not Peter,s marriage . According to Ancestry.co census his wife was born Eyemouth and he was born further north. Their marriage is not in the Irregular marriages 1808-1864 but Berwick archives has microfilm which includes dates July1850-November1850 so you might be in luck there Unfortunately the office which is in the Berwick library has been closed since last March but we hope it will be opening after Easter I,ll check it out if you haven,t found the marriage by then