I went from Gold in Portunus club to Caribbean in Peninsular Club too. Then I did quite a lot of cruising upon early retirement, and found myself in the Baltic tier, which I never expected to reach. I remember receiving lapel pins, though like you I never wore them or saw anyone else doing so. On reading this thread, I decided to have a rummage amongst my P&O souvenirs. So far I've found 8 Caribbean pins, all in little blue cloth bags, 3 Baltic ones in little cardboard holders, and a round blue badge for P&O's 175 years Grand Event.