In this scenario you take 444019 on a once a day early-morning stopping service to Portsmouth Harbour. I hope you enjoy this scenario. Please leave me any feedback.
DTG Requirements:
Portsmouth Direct line
https://store.steampowered.com/app/820203/Train_Simulator_Portsmouth_Direct_Line_London_Waterloo__Portsmouth_Route_AddOn/
European Asset Pack https://store.steampowered.com/app/208300/Train_Simulator_European_Loco__Asset_Pack/

Armstrong Powerhouse Requirements:
Class 455 EP Vol 2 https://www.armstrongpowerhouse.com/enhancements/multiple_unit/class_455_enhancement_pack_vol_2
Class 456 EP
https://www.armstrongpowerhouse.com/rolling_stock/multiple_unit2/class_456_electric_multiple_unit_pack
Class 158/159 Cummings
https://www.armstrongpowerhouse.com/enhancements/multiple_unit/class_158-159_cummins_enhancement_pack
Class 375/377 EP
https://www.armstrongpowerhouse.com/enhancements/multiple_unit/class_375_377_enhancement_pack
Class 444/450 EP
https://www.armstrongpowerhouse.com/enhancements/multiple_unit/class_444-450_enhancement_pack

Superalbs:
Class 166 GWR
http://www.mediafire.com/file/bf3ff2zimahcfkk/Class_166_-_Great_Western_Railway.zip/file

Sempahore Simulations:
https://semaphoresim.com/file/54-swr-444-450-reskin-pack/

Just Trains:
Voyager Advanced https://www.justtrains.net/product/voyager-advanced-2019

Recommended:
Armstrong Powerhouse Track enhancement:
https://www.armstrongpowerhouse.com/enhancements/general/track_enhancement_pack
Armstrong Powerhouse Sky/Weather Enhancement:
https://www.armstrongpowerhouse.com/enhancements/general/sky_weather_enhancement_pack