On Friday I received my second package from Tristan da Cunha. It was larger than the package I had received earlier in the week and thus had a 70p stamp:

The date stamped on it is 10 December. Inside was a recent issue of the Tristan da Cunha Newsletter. The postmark of the stamp on the package I had received earlier was 1 December, or what looked like 1 December. That day was a Sunday and the post office would not have been open then. Thus I am led to believe that both packages were posted at the same time. There was however no trace of a zero or any ink at all after the 1 on the earlier postmark.