The best picture I have found so far is this one:
http://www.geocities.com/steve_atlondonuk/astra2.jpg
I am beginning to think my memory has failed me on this car. I remember the back end as being taller than the usual fastback, but it might be an old age thing happening here. Mine - not the car. I'm a lot older than the car I'm looking for! It was my first car and I wish I had kept it!
Pat