Fully agree with Charlie, there is a lot of over-weathering in the 'modelling world' that ruins models - not only was equipment well looked after, but in most cases was at the most a few years old so couldn't get in the state some modellers depict them as - Tanks for example, by neccessity, during a war were new when in service, for example a Mk IV Tank in service at the end of the war couldn't be much more than a year and a half old at the very most.
Some of the most shocking weathering is in the aircraft modelling world where they look completely unairworthy and a pilot wouldn't go anywhere near!