Finding the 'right' colour of paint, even with a spec, especially an old wartime spec must be a bit of a nightmare. When I was restoring my old 1969 MIni Cooper during the early 80's I could never establish the metallic silver colour that Dunlop used to paint the wheels. So I used to carry a big wodge of silver paint mix colour chips and every time I saw a Mini or 1100 (another BMC rust bucket made from water soluble steel.....) I would lean down and see what was the closest match. There were hundreds of them! Even Dunlop just said the paint was just a 'service silver'. So I just bit the bullet and did them in a, well......., silver! Mind you, Dunlop were a bit like BMC with their lack of extravagance in paint with the motto 'never knowingly over painted'. The paint was about a micron thick. Just like the cars!