Lets wake up this zombie. TheHeadBadge data for Brooks Pros shows 2 different badges; v1 and v2. It says v2 lasted until at least late '79. I have 2 Pros, 1 small rivet and 1 large rivet that are stamped A 80 (first 1/4 1980?) that have the v2 badges so apparently they used that badge for a little longer.