No chance on a Newsagent having one (unless they are a collector themselves)
Best thing to do would be to get in contact with Nationwide News and see if you can't get a hold of the image via email from their editorial department.
If this isn't available, the next route would be to get a copy of it from mircofilm. Again Nationwide should be able to help you out.
Third option, if you can work out who the artist is "Boo"? maybe look to contact them directly.
Hope this helps.
Regards,
Mark. (A Newsagent!)