OP Thank you for the link.
My genuine "Z" key fob was taking a bashing at work (attached to my belt) so I ordered your linked item from Amazon.com with shipping to the UK.
I have transplanted my circuit board into the new shell and now my genuine "Z" shell won't get bashed up any more.
Seems like I am not allowed to give a review on Amazon.com as its my first purchase but the parts are a great fit and if ordered as a refurb or replacement casing for a "Z" fob it will do a great job. I guess the poor ratings people bought the wrong fob casing as Nissan use many different ones it seems.