With all due respect P&P, but that looks thicker than your standard, everyday navy blazer flannel. In the '70s my dad bought me a blazer before sending me off into life. I believe it was a Brooksgate blazer, with heavy wool flannel. Haven't seen anything like that jacket since.Looks to be a fairly standard wool blue flannel blazer with a turned up collar and possible double vents. Conclusion: you can get it everywhere.
You're right, it does. But it's difficult to see much of it from that particular photograph. I wonder what the poster sees that I can't....that looks thicker than your standard, everyday navy blazer flannel.