It should be completely compatible with all previous versions.
r06 - 29/09/2017 Changelog:
Added: KSR 6000 Series Steam Locomotive (Chinese Railways JF 2-8-2)
Added: KSR 150 Series Electric Locomotive (Converted Ganz DVM-4)
Added: Kanghaenggun Electric Locomotive (Converted K62)
Added: KSR 100 Series Electric Railcar (Japanese DeRoHaNi)
Added: Francorail-MTE CSE26-21
Added: KSR 4000 Series Chongnyonjol Kinyom (Converted Francorail-MTE CSE26-21)
Added: KSR 5400 Series Red Flag 5400
Added: Option to simulate the Oil Crisis of 1973, increasing the running cost of diesel trains by 50%
Changed: Names now correspond to DPRK classes. (Original names in brackets) (and for steamers even the wheel arrangement)
Changed: Purchase window sprites now have icons to indicate what type of train they are, courtesy of Purno.
Steam train hype

I did some more research and I found quite a bit of trains to make. It used to be a list of only a handful of trains left; an ALCO, and 4 steamers. Now we've expanded the list a bit to 2 diesel railcars, 23 steam locomotives, 2 EMUs, 4 Electric locomotives, 1 steam railcar and 2 electric railcars.
I really want to make a narrow gauge railway, but the only narrow gauge train for which I pretend to have enough data is an electric passenger car. There are also 3 narrow gauge steam locomotives; a Czechoslovak 0-6-0T, a North Korean 2-8-2 and a Japanese 2-8-0. I don't have enough information about these trains to really implement them. If you come across anything, please, shoot me a PM or leave a reply in this thread.