Class 142's never worked between Paddington and Reading. On a very few occasions a Class 143 worked up to Paddington on the overnight Wales & West service from Cardiff, if the 158 failed at Bristol returning with the 05xx or whatever it was from Paddington to Cardiff. But that only happened on a very few occasions and once the night trains started going to and from Waterloo via Staines any 158 replacement would have terminated short at Reading. As regards the Glossop line again unlikely. Before the 323's service was worked by Class 304 EMU's and prior to AC conversion the Class 506 1500v DC units.
142 is coming with Blackpool-Preston-Ormskirk by JustTrains, so you can put it on both with scenario planner. Don't need to make a thread about it, just check the news.
Class 142 has worked the Hadfield branch in the 1980s. Not sure about 90s but certainly in 1986 and 1989 images exist. Google "Class 142 Glossop".
