I agree there, I've seen z3m recent at around 11k, in decent nick. That only leaves 3500 to find all those parts.I love a project and I love a bargain. And I love the look of this car.
But my personal view is 149k miles (albeit with a rebuilt engine) and no interior means £8,450 is perhaps not quite the bargain it may at first seem. We'll see soon enough won't we as the bids come in.