Thanks for your prompt reply.  How far back can we go, then?  Ward boundaries seem to move for the local authority's convenience, but Chorlton's parochial boundaries would have changed with the building of St. Werburgh's, as the township expanded in almost all directions.  
And I seem to remember a Boundary Commission in the 1980's fixing the Manchester/Trafford anomalies. Longford Stadium, and an area next the TA Depot on Upper Chorlton Road shifted allegiances, as did The Jackson's Boat and Loreto College further afield.  Obviously I won't change anything until I can cite the source.  212.121.210.45