There is a good series over at AdaFruit about Casting Metal Parts from 3D Prints. I have done a similar thing but casting pewter from a 3D print of a birds skull. It turned out quite well, although I discovered how important it is to properly “finish” the 3D print. The next time I do this I will sand and paint the print to smooth it before casting. I definitely want to get better at this kind of thing.