For creating the cracked look of the diffuse I use a Cellular Map with Cell Characteristics set to Chip. The size is a matter of choice, it should match the proportions of the reference picture though. I lower the Spread that much the lines nearly disappear. Into the lower slot of the Division Colors I drag a Noise map, type set to fractal, colors around an RGB 128 and a little tone of blue. I increase the contrast via changing the values of High an Low Threshold. With this map I try to break up the uniform color of the Spread, if it doesn't work, try changing the values for size, levels or coordinates.
One level up - back in the Cellular Map - I equalize the values for the High and Low Threshold toward the Mid Threshold and - last but not least - increase the value for variation. Much better now, but I'm still not satisfied, so I copy the cellular map into the Cell Color slot and open it. In this map I do the same stuff like one level above, instead of using another map in the Cell Color I change the colors to some light grey with a little cyan or blueish tone and change the values for offset, tiling and rotation.
Back in the maps roll out I decrease the value for the diffuse down to 50.
This setting is not final, it should be changed after adding the next step, which is
I instance the Diffuse Map into the Specular Color slot and do a test render. If the colors are oversaturated I decrease the values for variation and the saturation of the colors in both Cellular Maps.
The value for the Specular Color can be left on 100.
Instancing the Diffuse map into the Glossiness and lowering its value to around 30 is quite the last step.
The blurred reflection adds a little extra to the material. It increases the render times drastically, but I think it's worth the time.
Add a Mask Map in the Reflection Slot, in the Map Slot I put a Fresnel Falloff Map, in which Side Slot I add a Raytrace Map.
For the Mask Map I use another instance of the Diffuse map, which I invert by checking on the Invert Mask box.
In the Raytrace Setting of the Renderer I lower the Depth to 1 and change the Blur Aspect and Blur Values in the local Fast Anti-alias Settings of the Raytrace map. Especially the last step boosts up the render time.