Read carefully!
---- I dont know if its working or not. Information from SteamDB, could be another Game as well. This is a Key for DLC - basegame needed.----

About This Game:
Build And Operate The Railroad Of Your Dreams....With Your Friends!
Trainz Simulator 12, Now With Multiplayer

TS12 includes the most exciting new feature in the history of Trainz. The players have asked for it and we have delivered Trainz Multiplayer. Now players from all over the world can build, play and operate railroads together!

About the DLC:
The Coronation Scot is a powerful steam passenger locomotive built for British railways in the 1930’s. The Coronation Scot celebrates the halcyon days of LMS passenger service by recreating the sights and sounds of this historic train, and is now available as part of your Trainz collection.

Entering revenue service on the 5th July 1937, the Coronation Scot was an immediate success in terms of speed, reliability, comfort, and publicity. Originally intended as a high speed adaptation of the LMS ‘Princess Royal’ class, the design process for the new locomotives resulted in the inclusion of a number of substantial improvements over its predecessor.

https://store.steampowered.com/dlc/24670/Trainz_Simulator_12/
https://store.steampowered.com/app/24677/Trainz_Simulator_DLC_Coronation_Scot/