This route is by 4 Aspect Simulations. You can find it here: https://www.4aspectsimulations.com/routes
(Based on a real timetable), written by Henry Pinkney. On a slightly windy but very hot afternoon on the fens, take Great Northern 365520 From Kings Lynn to Ely. Major disruptions from Norwich are affecting GA and EMT services so you may need to keep a lookout for red signals. Most unit numbers are represented as they were in real life.
Difficulty: Medium
Requirements:
AP class 365 EP (plus extra stock pack)
AP class 375 EP
AP class 170 EP
DTG class 800 (plus SimVue's LNER and TPE reskins)
DTG's London - Brighton route
You can find them here:
https://www.armstrongpowerhouse.com/enhancements/multiple_unit
https://store.steampowered.com/app/208280/Train_Simulator_London_to_Brighton_Route_AddOn/
https://store.steampowered.com/app/222618/Train_Simulator_East_Coast_Main_Line_LondonPeterborough_Route_AddOn/ (for the 800)