So I am looking around trying to find the seat unit that I have pictured and I just couldn't find one, so after after looking at numerous posts on countless websites on how to make your own, that is the route I took.  I made a plug from wood, then covered it in black gel coat and fibreglass and out it came.

Looking back at the above paragraph I make it sound so easy, it wasn't.  Not to say it was a very hard job, more to say that my initial skills in this department were lacking (i.e. none at all) and my 1st couple of attempts were woeful.