I can't find my Manchester area 1977 WTT but if I do I'll report back.
Found it: Section CM 2 May 1977 to 7 May 1978
Up weekday services:
1M25 18:08 Parcels Piccadilly to Saint Pancras D315 "Must not convey four or six-wheeled vehicles", calls at New Mills Central and Chinley, then used Dore curve, but I'm fairly sure no passenger accommodation. This sat in platform 11 most of the afternoon from my earlier recollection. However 3M12 21:24 Parcels Mayfield to Nottingham, 4E02 23:00 Parcels Mayfield to Doncaster, 4M16 23:15 Parcels Mayfield to Luton or Cricklewood, so it was interesting that 1M25 still used Piccadilly for a parcels service, maybe Mayfield was full and certainly Piccadilly at the time wasn't.
No weekday down service Saint Pancras to Manchester. I think the balancing working to 1M25 was the "Nunnery Vans", 5M54 13:27 Nunnery CS to Longsight CS, on which I once travelled in the back cab of a Class 25 .... happy days!
Sundays: I recollect both of these were passenger services. All called at Sheffield (Midland) so didn't use the Dore curve (WTT shows passing times for Dore station when using the Hope Valley route).
1M51 09:45 Piccadilly to Saint Pancras, via Dore until 2 October, Woodhead from 9 October.
1M84 18:55 Piccadilly to Saint Pancras via Dore
Down Sundays: also passenger services
1M32 07:50 Saint Pancras to Piccadilly (via Woodhead from 9 October as above)
1M49 18:22 Saint Pancras to Piccadilly