The first thing to go with water damage is usually the keyboard and trackpad assembly, and also the battery, the logic board as long as it wasn't a lot of water should be fine, at least with older retina and unibody MacBook Pro's. I would recommend ordering a top case and a battery. Then pray to whatever you believe in. Also do any of the chips on the logic board feel really hot when plugging it in. If so the logic board will need either a couple of chips replaced or the entire board. Also remove the logic board and check for corrosion as Dan said.
Hey according to some quick research the machine should be compatible, the biggest issue I could see is WiFi, please email me at firstname.lastname@example.org and I will do whatever I can to help, I’m fairly capable at hackintoshing PCs and have done quite a few Edit: make sure the subject is Hackintosh because that email is my dev email so I get tons of stuff