Looks ok....
Don't know why its listed as 'Very rare'
If the boot lining needs replacing its probably water damaged, through a leak below the rear screen so check the boot area for rust...
Wheels i beleive are AMG styling I's , which are ok, but not as sought after as styling II's are they 16's or 17's ?
Its worth what you think is a fair price for it, if you feel like you had a deal then thats what matters, there was a discussion on here a while back about the price of cars on ebay, and sometimes they don't reflect the true value of the car....
Why is the wooden trim broken on the dash ? is it where someone has tried to break in to the glove box ? check for other signs of damage ..... pieces of glass under the carpet etc....
Watch out for the chrome wheel arches, these add-ons are commonly used to hide wheelarch rust in order to sell a car on without having to have the paintwork done.....
I see its got no MOT and Tax, this would be the biggest worry as if it fails and costs loads to put right, then you have bought a lemon.....
To be honest KLP 92 is the guy to speak to, hes just bought a 560SEC AMG and is in the process of renovating it ...
Good luck !!