If you follow my link up-thread (
https://www.railforums.co.uk/threads/deltics-to-stockport.213589/) you'll see that I posted the 1977 working timetables which showed loco change in Stockport as well as a portion for Manchester Victoria detached at Stalybridge.
In 1980 the Stockport workings were similar: 0M41 00:20 electric locomotive Longsight to Stockport to work 1M41 from York which arrived just in front of the electric angine (00:21 into Stockport) and 1M41 departed 00:41. The down working arrived (1E24) into Stockport 00:36 with an electric engine from Crewe, and changed to diesel - presumably the one which had worked 1M41 from York - and left Stockport at 00:50. I don't know what the electric engine which had worked 1E24 Crewe-Stockport did next.
EDIT but in 1986 1M41 ran diesel throughout, 00:35 to 00:47 at Stockport, and 1E24 ran diesel throughout as you remember, 00:39 to 00:50 at Stockport.
Also, 14 May 1988 was the last time this train ran (date at Stockport on the Saturday morning, the new timetable started Monday 16 May 1988), presumably then also with diesel loco throughout.
FURTHER EDIT And, just for amusement, the down train was 1N71 [at that time York was in the North Eastern region] Aberystwyth-York (started Crewe MO) in
1968, also electrically hauled Crewe-Stockport, 00:38 to 00:52, whereas the up train was 1M41 still, 00:23 to 00:42 at Stockport loco change to electric, which also ran Sunday-Monday. In
1969 the down train became 1E24 because the North Eastern region was abolished and merged with the Eastern region.