Old Brass Material

Today I'm going to make an old brass material. This material is made in Blender / Cycles.

I have used the another node setup explained in the mango blog, different to the material of brass material. This is a glossy material with coating:
 

It uses a complex formula to generate the glossy factor, mixing the diffuse and glossy colors, and a fresnel node. The coating layer is white (RGB 0.8,0.8,0.8). I don't use the displacement part.

The final node setup for old brass material is as follows:
 

Bye