Nice stuff, I use 3DsMax too, but my railway models have a lot less faces than anything you've done, then again so far all of the equipment I've started modelling has been highly angular. I have considered doing something Spoorweggy but I already have too many money-pit hobbies, however that underscale Rivarossi unit looks like it would make a nice display model, I'm guessing it's long gone from shops.
Thanks
Chris H