Loco: Class 85 (although a McRat would be cool) EMU: Class 303 DMU: A.N. Other first-gen DMU. Need something other than a 101.
Class 108 the most obvious choice for a DMU to fit on the existing routes, though my grail would be a Swindon Class 120 Cross Country unit, backed up by a Cravens Class 105.
Loco: 1st Gen EuroSprinter / ES64P ( OSE-HTR Class 120 / CP class 5600 / Renfe class 252/ Siemens PCW8) DMU: Stadler/Bombardier GTW (Any variant) EMU: Siemens Desiro Classic
I think there was a mod for Wivenhoe in MSTS in the end, but I didn't mind at all, it was lovely to be able to drive through my adopted home and for its time it was the best value rail sim route I've ever owned. I'd certainly buy a North East Essex network. Basically be a Colchester-based driver without the London runs. But I'd happily do without the Clacton branch (for now) in order to get some long-distance 100mph running in a 720 and 745 (or whatever trains fit the era the route is set in) down to the big city. Clacton/Walton to London would be the route I'd build but I think the majority would prefer London to Ipswich plus either Harwich or Felixstowe for freight runs.
Based on that a 4-Vep would be a good shout. Perhaps do something with the Strawberry Hill people and chuck a few quid their way to help with the restoration.
For the Loco: The Br 120 from West Germany For the emu: The Desiro HC from Siemens (The DB, Averio or ODEG variant would be nice) For the dmu: The Stadler RS1
I know you just meme'd with the 139 suggestion, but I think I would make for just a fun little addition if they ever did a route through Stourbridge Junction.
