Old pic: [link]
CPO Matt Austin from Mobile Suit Gundam: Zeonic Fronts should be memorable to anyone who played said game. This badass refused to upgrade to the MS-06 Zaku II, Gouf, or Dom throughout the entire One Year War. The old vet upgraded his Zaku I with better equipment as it was made available, such as a Heat Saber introduced with the Gouf, several new bazookas introduced with the Dom, and a heavy shield salvaged from an RGM-79.
Update: I re uploaded the picture because of some heavy and much needed work to the shield. The old picture showed the shield with a single and sloppy wash of rusty brown but in the new picture, the shield was treated with salt and repainted.
How I did it
1. Paint silver chrome onto the shield
2. After the silver chrome has dried, paint on the color you want. Make sure your paint is diluted with acrylic thinner or alcohol.
3. While the paint is still wet, pour salt onto it.
4. The severeity of the weathering will depend upon how long you let the salt and paint mixture dry. I let mine dry for about 1 minute.
5. Rinse painted piece under warm water.
6. Dab piece with a towel
The result will be paint with a granular texture. To get a really nice beat-up feel to your part, go over it a few times with a few thing washes of Gun Metal.