First I did Juergen's method and merged down the two layers.
Now to improve the lighting...
1. Add a Level adjustment layer. These were the original Levels settings:
2. I moved the sliders like this to lighten the whole picture.
3. I went one step further to lighten the background. Added another Levels and moved the middle slider left. This however also lightened the men further which I did not want to do, so on the layer's mask I painted over the men with black to mask out that portion of the Levels adjustment and reveal the previous Levels adjustment.
Rather than painting black you can select the men and on the mask fill the selection with black. In either case if you revealed too much or too little of the first Levels layer you can fine-tune the mask by painting black or white as needed.
If the fix looks good before the enlargement it should look the same after the crop and enlargment. Just have to try it and see.
One tip I should mention...When you select the right eye/glass frame, select a little bit larger than the actual size. After the paste, use a soft Eraser to remove the excess. This way the edge of the patch will not be noticeable.
If you want the changes I made I posted it at
Right-click it to save to your PC.