I am sorry to tell you that your air twist glass is not old glass. The old air twist glass was made in the mid 1700 and there was no coloured glass made at that time. The foot of old glass is always very thick . If you look at your glass they are bright and perfect. In fact l saw a modern air twist glass the other day at the charity shop for 50p(made in Czecholovakia,engraved 1988).
Sorry to tell you the bad news.