Well, another search has provided me with the answers I was looking for. The book I was referring to in my last post was ‘Conrad – The factory made boy’ by Christine Nostlinger. It is described here;
“In this clever tale, Conrad is a made-to-order boy who has perfect manners. When he is accidentally delivered to the wrong person, Mrs. Bartolotti, who does not demand perfection from Conrad, the boy bonds with his new family. When the cold and demanding parents who actually ordered the “perfect child” arrive to regain their lost delivery, Conrad must quickly learn how to be naughty so that he can stay with Mrs. Bartolotti.”
Just purchased it on ebay for £1.20 plus postage. Cannot wait to get hold of it and read it to my eldest (we need a break from ‘A Series of Unfortunate Events’). Once I have done that, I am going to write a review. By the way, the Book cover at the top of this post is the cover art I remember as a child, but I am receiving a paperback copy with a different cover. Looking forward to this, as I read it numerous times as a child and never tired of it.