Try checking with any UK vintage auto clubs with members having US autos. Just a guess but would think your 49 year old auto could be exempt from the current new car standards. Last Nov. I imported my 1966 from the states to Canada and was exempt due to age. Occasionally I check in with an AUS T-Bird forum in Victoria and have not heard of an instance where those 'down under' had to change their T-Bird lighting to import.
Free forum : Thunderbirds Victoria