Yep - have to add that Steve is correct on this one, the 'side hats' didn't appear until late 1939.
In fact in 'Fighter Pilot' written by Sq/L Paul Richey in 1940/41, whilst he was recuperating from being shot down in the battle for France whilst with nos 1 Sq, it is mentioned that they were first issued with these just prior to shipping out to France.
