What about the Liverpool St - Kings Lynn services? These ran, usually with a 47 and Mk2s, right up to electrification.
Apart from they also ran after electrification to, with a loco change at Cambridge from a Class 86 to a Class 47.
In actual fact, just before, and after electrification, there used to be an hourly loco hauled service to London from Cambridge. With the through service from Lynn being two hourly.
If memory serves me right, the end of loco hauled services was in the 90's when through services went over to Class 317's supplemented by the use of Class 101 DMU's filling in on some services between Cambridge and Lynn (if memory serves me correctly, this was because of a lack of 317's, which were being transferred from the Bed-Pan route).
Platforms
thats true but I recall them stopping around 1989, there were replaced with EMUs - I think 317s between London Liverpool Street and Cambridge, and DMUs between Cambridge and King’s Lynn for about 2 or 3 years. I think when electrification was completed the main through services diverted to London King’s Cross with only a couple in the morning and evening peak running through to London Liverpool Street, but there was definitely a period when every train terminated at Cambridge - I would estimate it was 1989-1992 but can’t be 100% certain.
Sorry but that isn't quite correct, as there was still some through services which were loco hauled. They were predominantly the "rush hour" services into and out of Liverpool St from/to Kings Lynn, this was certainly the case up until at least 1991 when I found a new hobby... girls !!
Edit : For clarifaction.. The electification of Cambridge (and relevant services) was done in 3 stages.
1) Bishops Stortford - Cambridge
2) Royston - Cambridge (in actual fact Shepreth Branch Jnc).
3) Cambridge - Kings Lynn
Class 317's operated predominantly between Cambridge and London Kings Cross and only started operating through services to Kings Lynn when Kings Lynn was electrified and services from there predominantly ran into Kings Cross rather than London Liverpool Street as previously.