I too am curious about the Southwick Douglas model. And I too wear a vintage 346 navy sack blazer, about which we seem to differ: I love it.
I heard good things about the sack blazer from Southwick, Douglas model.
But personally and unfortunately. I don't think I have a decent quality sack blazer I can depend on. :icon_pale:
My most reliable navy blazer is a vintage sack from brooks 346 shop. I would say its alright, but I can use a better one.