On two of the original doors, I removed the heavily painted hardware and used a low heat (200F) overnight bake with some dish soapy water to strip the paint from the old cast iron.
I then primed and painted them gold. For the detail inlays, I used some thinned black enamel paint and a Q-tip to fill in the low spots to make the designs pop. I then hit them with multiple layers of clear lacquer to seal them. They have yet to be re-affixed to the building; we will wait until painting is complete!