You are correct about the 1976-77 reg, so as you say, it must have been an import.

The little Cooper has gone home. Still a shame to see a car as cool as that leave our shores. I am surprised no one in Ireland bought and restored it.

AYI to 999 YYI9 (Mar 1976 – Jan 1977)

http://en.wikipedia.org/wiki/Vehicle_registration_plates_of_the_Republic_of_Ire land