Open Terminal and type:
ioreg -lw0 | grep IODisplayEDID | sed "/[^<]*</s///" | xxd -p -r | strings -6
It will show you exactly which screen you have.
You can also visit
http://www.chipmunk.nl/klantenservice/applemodel.html
to get information about your mac, entering the s/n.
The site is dutch but with english translations provided.
There are a lot of different screen specs on the MBP range which are not always interchangeble.