Thanks, I was going to say: Here is Seb wearing his! Is there some significance to the two piece back? I thought it was mentioned here once. I don't think I have seen another.
It IS me wearing mine.... I've seen another with a back seam - once on ebay. Sometimes there are odd variations. Ive seen a range of snaps used, a different wind flap (one piece, double sided instead of the ususal cotton bound one piece single sided leather version) also differerent lining and interior zips. I think they started making these in the late sixties. Brooks were started by the the guy who made Buco, Joseph Bugeleisen.
Interestingly enough Reed made jackets just like these (almost identical) in the 1070's.