So much to say .
1) It looks like Sky Blue 9656 , otherwise known as the Hambone. It is a bit off spec in that normally they are about 4.5 inches wide minimum, but it still retains the Hambone shape.
2) The 9572 you mention in Arctic Blue and being heavily cased, will not be Arctic Blue as this colour was not cased, never, ever. Do you mean Kingfisher?
3) Re: damage to rim. Yes you should ask seller for some kind of partial refund to take this into account in my view. But the price you paid was very reasonable for this Sky Blue piece, even with the postage, and the condition ( could be polished out perhaps?) One just recently sold for around Â£60 on ebay uk + p and p, and even this was cheap as they used to go for much more before the general slump in prices.
Here's a pic of mine, as you can see the extra half inch on the width makes quite a difference to its appearance