This one has just come into my possession. Joseph Sankey & Sons 1940 with liner marked 1939 and size 6 3/4. I can't make out the entire maker's code. It looks like _TC and a symbol with a couple of numbers (66?) over it. The lining retention bolt looks replaced and the top lining pad is missing. The blue certainly doesn't look like any WWII RAF blue I've seen, so I wonder about it. Any thoughts, anybody?