Here is my opinion about Rail Station Markers and Rail Markers.
Railing Units takes part in Non-Combat Movement.
Any Land Unit can Move/Rail up 4 Territories. (I feel the range must be the same for all land units)
-It has to start in a territory with a Rail Station Marker, but can stop/off-load in a territory with a Rail Station Marker OR Rail Marker.
-The Rail Capacity is the same as the Territories IPC value. A Territory with a IPC value of 5 can rail up to 5 land units, this also the number of units it can receive. A territory with IPC value of example 3, can only Rail 3 or receive 3 railed units per turn/round. A territories Rail Capacity is the same as the territories IPC value.
Rail Station Marker Cost : 10.IPC (Can both Rail/Receive Railed Units)
Rail Marker Cost : 5.IPC (Can only Receive Railed Units)
Or to make it more easy:
Rail Station Marker [Cardbord] : Gives Land Units with a Movement of 2, +1 Movement and Land Units with Movement of 1, +2 Movement. This way you can Rail (Move) all Land Units, Infantry, Artillery, AA Guns, Mechanized Infantry and Tanks 3 Spaces/Territories. I think that would make sense.