Here is a pic showing the raw wood hand rail at the bottom of the stairway.
Since I wanted an all-iron look, I decided not to stain the handrail. Instead, I did a metallic paint treatment that had texture that mimicked metal. After priming the raw wood, I applied texture (weathered bronze lusterstone) with a chip brush, and lightly sanded after it dried. Here is a pic of the lusterstone after sanding.
I then applied a metallic paint glaze (mixture of two Modern Masters metallic paint colors plus some glazing medium) to match the spindle color. Finally, I topcated with two coats of polyurethane.