Some years ago Steve Purcell offered his original (print?) of the background of the cover on ebay.
Artists also need money to eat something. I didn't have the money for that but I saved... the images ....
And now here they are for you to see:
I would have had recognised Dinky Island after 3 found map pieces already!
If you are the person that bought these and you are actually reading this, drop me a line if you want to share more photographs of it :)