Don't know if theses are the one syou are looking for as the online electoral rolls do not cover most of Smethwick but:
1930 Florence & Arthur Bradley, 57 St Mary St (with Walter & Rose Rowley, William & Lily Whitcomb & William Strawbridge & Annie Ward)
1935 Florence & Arthur & Albert Henry & Martha Ellen Bradley, 128 St Marks St
In 1939 there were two couples, but both had extra christian names and were not in , so were probably not the same ones
1939 Arthur Edward & Florence Elizabeth Bradley , 18 The Retreat, Bordesley Green Road
1939 Leonard Arthur & Florence Cecilia Bradley ,82 Shirley Road
The only ones before 1930 lived in Kins Norton area and were also listed in 1930, so cannot be the ones required.