https://upload.wikimedia.org/wikipedia/en/e/e8/Class_157_Strathclyde_Sprinter.PNG
I'm not aware of anything else on the horizon for Regional Railways other than the abortive Class 157 and WYPTE Class 323s. However, moving into the mid-1990s I could have seen Regional Railways looking at: -
- Class 101 replacement for North West and Strathclyde PTE services.
- Class 303 replacement for Strathclyde PTE services.
- Class 305 replacement for North Berwick services.
- Class 310 replacement for West Midlands services.
- Loco-hauled replacement for North West services.
The Class 157 would have been interesting as it could have replaced the 101s and 156s on Strathclyde - the latter could have been cascaded to the North West to replace the loco-hauled services.
If the Class 323s for WYPTE had been approved then a further follow-on build to replace the Class 303s could have been on the cards (possibly with a small sub-fleet to replace the 305s on North Berwick services).
Replacing the 310s in the West Midlands would have been interesting. Likely (I guess) to have been pitched for more 323s.
That would just leave a potential gap of replacing the Class 101s in the North West.