The technology certainly could be used to reproduce valuable chips, either to collect, or to play in the casino. I'm sure part of the incentive for the chip manufactures to introduce more counterfeit detection schemes into their product is related to the 3-D process improving and becoming cheaper;.

I don't know if anyone has tried thus far, but if he is motivated and knowledgeable, he could certainly reproduce old casino chips. It's likely that with sufficient technology, an expert could tell the reproduction from an original. If 3D printing continues to develop, we may find that sealing expensive old chips in a container with the statement of authenticity of an expert may be come necessary. Not to say we will need chip "graders", but an expert's testimony as to authenticity may be needed. Other hobbies like autograph collecting and sports memorabilia collecting already have seen the need for such services.