I have tried both models on my MB Pro 15" Mid15. Although both fit perfectly (all connectors do too, except for the camera on the 2012 model) the backlight doesn't work. So you really have to use the right replacement part.
You can try to shine a flashlight through the Apple logo and see if you can see a faint picture on the display. If so, then there's a problem with your backlight. It's quite easy to open up the MacBook and check the cables. Just follow this guide (not the exact same model, but close enough): MacBook Pro 15" Retina Display Mid 2014 Display Assembly Replacement If checking the cables doesn't solve things then your backlight fuse might be fried and has to be replaced. This is a board level repair so very difficult to do yourself.
It fits perfectly, but the backlight doesn't work. Trust me, I have tried both model display assembly (2012 and 2013/2014). The screen fits and the connectors do too, however the backlight doesn't work!
I can tell for a fact that the other 2 models Dispay Assemblies don't work with the 2015 model. I'm having the same problem and tried both versions (2012 and 2013/2014). Although the screen fits perfectly and the connectors fit the backlight doesn't turn on.