I have a copy of Bartholomew's Survey Gazetteer 9th Edition which has Great Britain 1931 Census/official estimate populations. It lists what then was county boroughs, municipal boroughs, metropolitan boroughs and urban districts in England & Wales and cities & burghs in Scotland. This was (probably?) at the peak of the passenger railway network.
Canvey Island 7,000,
West Bridgford 23,000
Chadderton 30,270
Shaftesbury 3,093
Arnold 19,000
Only these were boroughs/urban districts at that time, of those discussed above.
Of these Middleton Junction was within Chadderton UD, its western boundary being about 0.1 mile to the west.
Arnold UD's western boundary appears to follow the centre of the double track line where it passes Daybrook!! SO ITS NORTHERN PLATFORM WINS.
Edwalton Station was easily in West Bridgford UD.