Hello I accidentally spilled water onto my macbook pro's keyboard. The repair shop has offered me to fix it by replacing the upper top casing of the unibody, but due to the repair fee being very expensive, I am considering doing it myself. My question is: Does the upper casing have to be from the same year that my macbook was produced? I have 13inch Macbook pro from early 2011 (April). Any help would be highly appreciated. Thanks in advance!