They all can be replicated either by taking a photo of them and enhancing the photo then setting the cut depth which is fairly quick but not super accurate, but can be tweaked into a very accurate piece.... There's a cool device called a CNC probe that can follow every contour of a sample and replicate it within about .02mm of the original which is damn near perfect, and then there are 3d laser scanners that take things a step further as they can scan every surface of an object to be replicated with about the same accuracy, the probe finds the contours mechanically and takes about an hour to copy a small object, but the laser scanner takes about the same amount of time and can copy every surface by doing a single scan then repositioning the object and scanning again, then lining up (index) points it can convert the 2 scans back into a single 3d model that can then be replicated either with a CNC setup or a 3d printer etc...
There's not much that can't be replicated with CNC machines, anything as simple as a license plate to as complex as a turbo impeller wheel, or even more intricate can be done by adding a 4th and 5th axis to the machine.
Mine is a 4 axis and I rarely use the 4th axis.. mainly because I need to practice more with just 3 axis before trying the more complex stuff, and a 5th axis can be bought and added in later if needed... or if I really want to go that far... Right now I'm plenty happy with using only 3 axises until I get better at this.