Yes the scale isnt there quite yet, the actual ottd dimensions put the true scale out the window totally. for example to fit one carriage of this train into 1/2 a tile's length would probably mean losing all but 2 of the windows (like the passenger carriage in Ottd), in ottd's case the length of one carriage in real terms is just over 6 metres (if a tile is 12.5), whereas in reality most british rail carriages are around 22 metres.Looks.. okay. Getting there, although there is quite a bit that doesn't seem to scale. I guess it may be unnoticeable with OTTD's scale.
The sides are also the wrong shape. They don't slope all the way down to the bottom. There also doesn't seem to be enough space at the end of the coach for doors and the last window, but I guess that's just changing the texture a bit.
Not sure what you mean by not sloping all the way down to the bottom.. but i can see that the termination of the slope could be higher.. as for the doors and windows in this current iteration it isnt of absolute importance, it will come in time.
I'd say you were right on that oneSorry if I seemed to criticize this a bit, but I'd say I have a very good eye for detail, so I can see where things can be improved easily.

Thanks
Mr_worf