I have once been given a 2012 MBP to repair with the casing completely damaged beyond use but the logic board was okay, I stripped down an old 2009 MBP and fitted all the items from the 2012 into the 2009 and yes it fitted, there was one screw mounting point which was not the the right place but this did not effect the operation of the logic board.

In short it will fit as all A1278 model MBPs are design with the same fitting apart from that one screw position, which is near the display cable BTW.

Follow this guide to show you how to fit the new logic board.

Let me know how it goes and as always if you need anymore help please just ask.

Cheers

Brendan Mills