Those Summertime Tracks

I have a Korean War summer 1950 Pershing tank in the stash and had to buy aftermarket tracks because the Hobby Boss kit types were the wrong type. The problem I have is, how to make them look right? Painting dark metal only really works for tracks having been polished by sand, but I’m sure that even in dry, dusty weather, some rust must be on the metal surfaces. Any picture of such a surface?