Chrisyross: get your ECG done ASAP. Forget the costs, you have a deadline time wise and thats what counts, no?
When the results come back, make sure the reporting officer annotates your notes accordingly so that future medical renewals don't keep re-inventing the wheel with you sending you down the investigative route every time you have an aviation medical. Once it's in print on your records, it's there for everyone to refer to when/if they 'discover' a glitch o the ECG. Ocassionally the CAA 'may' need a review of your predicamnet after 'x' years to see if the situation has changed.