And this Chester Barrie / Hawkes & Co (?) sport coat is definitely hella-vintage, and definitely available.
Warning: Spoiler! (Click to show)
Replying to my own post, because I'm just that self-centered. I haven't found a lot of info about the Chester Barrie/Hawkes & Co. connection. However, as I understand it, Barrie was known for making ready-to-wear garments for different shops, so I assume that they made this line for Hawkes & Co., sometime before 1974, when Hawkes joined with Gieves.
At any rate, damn that's a cool coat!