The ends of a very slender Whitworth wrench I picked up recently. The British Broad Arrow identifies it as having been made for the War Department. The "1954" stamped on it is likely a production year.
The only British firm I can find that might fit the bill is the Athol Engineering Company of Manchester. They made leaf springs, so perhaps they made tools for the military during WWII and for some times afterwards. Or perhaps the manufacturer was another company entirely.
If I mislay the tool, I'll have to be careful not to be misheard when I complain, "What did I do with that Athol wrench?"