Okay right now I'm using an iPhone 6s rose gold, the motherboard and screen (with finger print reader) is from a space grey iPhone 6s. It's working fine. like 100% fine. No issues what so ever. I'm not sure what you're trying to say, I have legal access to both devices.
If you want to know exactly what I'm saying keep reading.
I want an iPhone to match my rosegold Apple Watch so I'm getting an iPhone 6s rose gold with a black screen and black finger print reader. (Parts from space grey 6s) However the mother boards and finger print readers are a set, they won't work with each other. I have my information on the space grey mother board. I'm getting an iPhone 6s in rose gold and I want to drop the space grey motherboard into the new body with new hardware. I already have one but the body of his one is damaged. I wanna know if my data will be untouched.
Basically, I have access to both devices and I'm taking them apart, I'm gonna swap motherboards. Will my information be on the motherboard or is it stored somewhere else? Will ALL my data be on the motherboard?