i have a late 2013 iMac that fully decked out with the 3.5 I7 and 4GB video card, nvidia I believe (I'm not at home). I've been wanting to upgrade to a 5k retina iMac but since I already have a really nice machine it feels like a waste. I saw 5k retina panels on eBay for around $400 and thought about buying one to swap out with mine. Does anyone know if it's compatible? If someone did it, is there a write up somewhere?