Chosen Solution
My dedicated GPU was failing a few years ago. The Apple Genius Bar repaired it back then, I think my GPU is going again! I’ve found a MacBook Pro A1398 15" Early 2013 Core i7-3740QM 2.7GHz 8GB logic board which I’m capable and equipped to replace IF it will work! Will it work?
Sorry but no, not possible, the two Macs don’t have almost anything in common with each other.