Chosen Solution
iFixit has three logic boards listed for 15” mid-2012 MacBook Pros. The descriptions are the same except for the processor speed (2.3, 2.6, and 2.7 gHz). Are they interchangeable? I have no idea of the speed of my broken Mac. Also, minor point, why is the 2.6 so much cheaper?
They should work as the only difference is literally the CPU speed. You could also check the speed of your Mac via either iFixit’s Mac identifier or something else (serial number check, etc)