In response to someone I continued this thread with:

I wish I could remember what the book was called and/or who wrote it! Sadly I think it was a book we borrowed from the library so I won't be able to find out by going through my Mother's collection. Having thought of it now I really want to get a copy to give to my nephews.

to which jenn_calaelen replied:

Good luck finding it! I know there are a few book search comms/websites - where you put a description and see if other people remember it. :)