I think you can be exempt from ICB if you have right level of recent qualification. Think you have to pay for these exemptions though which I believe costs the same as the exams, and that you have to send of the certificate for someone to work out if you are entitled to the exemption. I was going to go down the route of exemptions for experience but did not because it cost the same as exams and would have had to get an accountant write me a letter.
Congratulations, you now have a highly valued qualification as AAT qualificationsare well recognised in the accounting/bookkeeping profession. If I were you I would stick with the AAT qualifications as they are well recognised in commerce and industry as well teaching you the knowledge for doing bookkeeping work. The AAT qualifications are also nationally recognised by the national qualification authority forthe United Kingdom.