This is a DCSV for the Bossman Games Southern Railway S15 DLC
Place the folling locations

S15 Pack 1 (Southern Railway Green & Black)
C:\Program Files (x86)\Steam\steamapps\common\RailWorks\Assets\BMG\S15Pack01\RailVehicles\Steam\S15\SR_Green\Engine

S15 Pack 2 (British Railways Black)
C:\Program Files (x86)\Steam\steamapps\common\RailWorks\Assets\BMG\S15Pack02\RailVehicles\Steam\S15\BR_Black\Engine