It clearly hasn't been looked after, I wouldn't want to waste my money. It needs too much work and who knows how much longer the engine will last if you think it's been ragged!
Have a look at the Zeds for sale section on here.
Too much work?!
It needs a new seat and some touch-up to the rear bumper......if you get that car for under £4500 its a bargain.
I looked after my Zed meticulously. Some would say anally, yet I still had a cracked front bumper and a tear in one of my seats. Both occured due to unforseen circumstances.
To say this car "clearly hasn't been looked after" is a massive assumption on your part.
The OP should go see it in person, and then make his decision based on that. Not on us lot waxing lyrical over a condition of a car none of us have seen in person.