I would be interested to know how many now–closed routes/lines were operated by "Paytrain" DMUs (even before Corporate–Era British Rail advertised them as such!)
You are right that
Paytrain as a method of revenue collection and
Paytrain as an advertising strapline are two different things. On the latter
"It pays to travel by Anglia Paytrain" is probably the first railway advertising to seep into my childhood brain. But I'm not sure that was introduced before the closures finished.
I travelled on the Cambridge-St Ives line once before closure in October 1970. My child single Cambridge-Histon was 8 pence in old money with the ticket sold on the train from a Setright ticket machine that I was much more familiar with on Eastern Counties buses.
Presumably the Norfolk ones:
Lynn to Hunstanton
Lynn to Norwich
Yarmouth to Lowestoft
Cambridge-St Ives was the last Anglian closure, going backwards from there are:
05/70 Lowestoft-Yarmouth South Town
09/69 Wymondham-Dereham
05/69 Kings Lynn-Hunstanton
09/68 Kings Lynn-Dereham, Magdalen Road-March
I think the September 1968 closures are the marginal cases where I'm not sure whether
Paytrain was ever introduced. So Wymondham-Dereham could have been
Paytrain but Kings Lynn-Dereham not.
so therefore also the Aldeburgh branch (Suffolk) presumably?
Saxmundham-Aldeburgh closed in September 1966, so presumably not. Similarly for these closures:
01/68 Cambridge-Bedford
03/67 Shelford-Marks Tey, St Ives-March