All I wanna know is where did Threepio’s red arm go?
rewatch TFA
Does TFA explain it? I know he has both his arms golden at the end, but does the movie give us a reason?
TFA doesn’t explain it (not a very good way to reply to someone dahmage…), but on the last shot - when the Falcon leaves the Resistance planet - you can (barely) see 3PO with both his golden arms.