Thank you Jonathan, I have indeed moved on since I first posted, I have a Cayman88 and am in the process of fitting a shelf. I have fitted the electrics, running down port side from the second recreational battery. Having researched and planned it out it has been quite a straight forward job, the hardest part is making a two part shelf out of  18mm ply and west system epoxy and fitting it through a relatively small opening. I will produce an article on the job for interest when completed.