Not sure why the Class 89 'Badger' isn't already in TSW2 but it should be. Its white & grey with a red stripe Intercity livery is an absolute classic just like the Class 43's. It'd also be a great canvas for the livery editor—especially after this news: https://www.railadvent.co.uk/2021/12/mainline-operator-confirmed-for-class-89-badger-locomotive.html
probably because it's a one off design so scripting the AI will probably be a pain and that it only really ran on the ECML which we don't have yet in game..
