1780 is the most common date found on Maria Theresa silver thalers but if there is an X after the date it shows it was struck in London! The Arabs wanted thalers so that's what they got. When I was in Aden the administration tried to introduce the 'Federation dollar' to replace it. To say that was an unpopular move would be seriously understating the case. At least one Political Officer was killed because of its attempted introduction.