Thanks everyone, i have based this on late war camo in France. Today i have done the oil dot method and blended with turpentine.
Then i added the lighter negative chips with a lighter colour of the original colour with white being added.
Then i added the darker chips inside the lighter ones just leaving a tiny amount of the light chip as an outside edge to represent the chipped paint.
I then blackened the tools and the gun and started to add some light rust streaking around some joints and fittings. After this i added some metal wearing with a lead pensil but try not to get carried away with any of the above techniques as little is sometimes more in effect.I then added some streaking down the sides and leaded up the MG. This is now ready for me to do the tracks and silver the wheels where they meet the tracks and the weathering with pigment powders which will really bring this dude to life.