if you bother to look. Pathe News has lots of images of troops in Greatcoats during the last three months, there are even shots of embarked troops from Dunkirk returning in full Greatcoat order!
Also look at the troops entering Belgium, especially those on vehicles and carriers who are often in Greatcoat Order.
I dare say there would be quite a number of useful images on IWM too.
Hope that helps.