Insert on a new layer the texture of an old wall:

fairy tale - rainy day - 
photo effects

Select the Clone Stamp Tool to hide all those exfoliated zones on the wall, just not to make dirty our picture.

fairy tale - rainy day - 
photo effects

Change the Blending Mode on Multiply and make the corrections on the brightness firstly (ctrl+m).
   


fairy tale - rainy day - 
photo effects

Then make the corrections on the color (ctrl+u).

fairy tale - rainy day - 
photo effects

We have to merge down all the layers (shift+ctrl+e) and make the picture a little brighter than it is now (ctrl+m).

fairy tale - rainy day - 
photo effects