I bought this from Technotronix for my MacBook Pro 2014 but then upgraded to a MacBook AIr. It is right for this model and also the 2013 model. It is unused and still sealed in the box. See item specifics in photos. You can install it yourself but best to let a tech person do it as it can be a fit fiddly. It currently retails at £64 on eBay.
eBay