I have noticed on some of the pics, Coupes with a bumper on, our's is a 1982 with flat back end, can you get bumpers or was that the design at that time, any ideas.

Your registration date is...... not that helpful in narrowing down which style rear you have.
For instance I know of a Heerey that wasn't registered till 1982, but there wasnt any sold after 1972.
So here are some photographs which may help you.

Or you could post up a picture of your car.





Picture 1. Cox Gtm Rear end


Picture 2. Heerey Gtm rear end


Picture 3. Gtm Coupe rear end

Cheers for photo,s ours is an 82 build looks like 1st 2 pics with flatter back, after looking at rear bumper ones have decided not to progress bumper, prefer the flatter type. Will post pics as soon as sorted have a problem downloading from Samsung to computer for some reason, will get sorted as lots of pics of strip down to poss help others.
If you check on New Members, Nick Hind, my son he has posted part strip on there.

Right I've had a look at the pictures, and think that your car is a........

Early GTM Coupe, (1979-80ish) from Paddy and Peter era, I can't quite tell if it's the early 12" arch model.