One thing with 3D printing at the moment is that it still takes a lot of cleanup once the object's been printed. I've worked with several different printers over the last 10 years and only seen one printer that prints fairly smooth as it comes out of the printer but still needs sanding and cleaning up where the support sprue's are (this is so the object doesn't collapse when being printed). I deal with these prints every day and the time and effort that goes in making one perfect object is pretty immense.
For me I think it's going to be a very long way off before something is even close to looking like a vintage item, let alone being financially worth while. There are a lot of different plastics and rubbers they print in (and even metal although it's powder based I believe), but they don't look and feel like vintage parts. I'm sure one day they'll get there but it just feels like too much effort at the moment for something that's probably not going to look great, the reproductions out there already are much more accurate and far cheaper to produce (unfortunately :evil: ). Remember that the first link posted up of the X Wing gun is just a digital picture and not the real thing which would have a lot of lines in it when printed and would take some time to sand smooth.
It's not great for us collectors but not really much of a problem at the moment (although I wouldn't mind getting the plastic parts for my miniature Palitoy Death Star printed
).
Ian