63 Dart bezels and 3D printing?

Depends on the material. Your typical "home" 3D printer will not print using materials that can withstand weather, heat, moisture. There are some good plastics such as nylon and ABS that can be printed. Metals can also be printed. But all of these are done with industrial type printers. Your best bet is to get the design perfected, then send off your stl model to a company like Shapeways for printing in your choice of dozens of materials.

I've (well my partner hasn't and I have not even tried) not had real good luck getting the parts made correctly from shapeways on a couple parts. I prefer 3d printing,cleaning up the product. then making a mold and casting the part from Impact resistant plastic resin if I can or send out to a small hobby foundry, Though I do have to find another one since the guy just retired this year and he was supposed to cast me some 1966 dart rear tail light bezels when I got the 3d printed pieces to him.(dang it)