I printed in grey PLA on ultra-fine setting. I printed perfectly. I now need to learn about finishing techniques... I am posting how it looks just out ofmthe printer. It still needs a touch of sanding and some paint shading and one would never see the difference from my Tardis key I got back in 1986.
I included image of the front and back with my old metal key to show how accurate RobTFirefly's design. The minor differences are due to the fact that the metal key in the photo was Tom Baker 4th doctor era, and this is modeled from 8th Doctor.
Be sure to pay attention that the orientation of the Tardis key so it can print on the smoothest surface.
I had 3 peices of tape butted up nicely, side to side, to cover the print bed, which left a tiny line on the back of the print. Next time, I will put the tape strips front to back.