If you can pinpoint an ancestral home the more than 1,300 new maps of England and Wales, from the National Library of Scotland, could help dig deeper. They show for various years from 1900 to 1972 the Administrative Counties, Municipal Boroughs, Urban and Rural Districts, and Civil Parishes needed to know where in the administrative structure relevant records would be found. The maps were usually published for each county in England and Wales at a scale of half-inch to the mile or 1:126,720 (metricated to 1:100,000 from the 1960s).
There’s a convenient graphic interface here.
On selected sheets, Parliamentary Constituency boundaries are also included (usually shown in green), as well as various Judicial Boundaries, including Commission Of The Peace and Petty Sessional Divisions (usually shown in blue), ca. 1966-73. boundaries in the 20th century. These include administrative and judicial areas and show their changes over time. All are prior to the major changes in 1974.
A complete list of recent map additions by the National Library of Scotland is here.