Thanks for the reply dropshort. I would be interested in the shapeways loco bodies, coaches, wagons and cars.
I'm in rented accommodation at the moment so n gauge is the only scale I can realistically work with, and even then it's taking up space in our shared garage. I like the look of n gauge. I'm not worried about everything not looking totally prototypical. It's a representation of the real thing, it can be a little abstract :-) I'm in my 30s so my eyesight is still good too. Bonus.