Ok, we need to know the source of this problem. Do you still have your old screen? Or another screen of any sort? You'll need to plug it in and calibrate it and see if the same problem arises.
Oh, this is always tricky.
You need to begin by cloning the people out of the darker photo. So that it's just a photo of scenery, you know? That removes a lot of the difficulty of "lining up".
All the channels are too damaged for any kind of "rescue" of those areas. It'll just be painstaking cloning, and/or swapping in areas of detail from another shot.
You don't need new prints. Of course your lab don't change they way they print just because one of their customers got a new calibrator.
Please check the prints you already have.