The one linked at the bottom of the same page looks ok-ish too, I much preferred it's layout, but didn't like the sharp edges and the gap at the rear.
In the back of my mind is the idea to make a rough one up with MDF then round the edges off a bit and use that as a mould, then coat it with fibreglass and lots of coats of paint. Alternative idea is to make MDF as said but simply cover it with leatherette type stuff (or maybe tartan material, yes I'm Scottish, and use same tartan to make new seat covers etc.)