I'm a bit late coming in on this, but I was out of town at my photography/Photoshop class.
I played a few minutes with your photo, and using a lot of what I learned in my class, I think the majority of this photo could be corrected using curves and the layer masks that go with the curves adjustment layers. You'll still need to use the clone and healing brush tools, but the 3 faces need very little repair after working with curves.
I'm short on time, but I'll try to give a quick summary of what I tried.
Using the original image, I chose the white and black points using the Threshhold adjustment layer tool. Move the slider to the far right and gradually move it left, until the first black dot appears, and hold shift and click on this, giving you a black point. Then, move the slider all the way to the far right, slowly moving it to the left, until the first white spot occurs. Shift click on this, giving it your white point. It may take more than a few white or black dots before big enough to give it the black/white point setting. Now, click cancel. You just wanted your black and white points. The purpose of doing this is to remove the color cast.
Next, go to curves, click on the white eye dropper, and then click on your white point marker. Then, click on the black eye dropper, and click on the black point marker. Click ok.
Now, you can go into curves and do multiple layers of curves if you need to. For example, the curtain on the right side of the photo was very faded. I did a control-click on the faded curtain, and lowered the curve until the curtain looked to be the right color. The rest of the picture looked horrible, but that's ok. I clicked "OK". This leaves you with a layer mask filled with white. Fill the layer mask with black, switch the paintbrush color to white, and with a soft brush, go over the curtain you just darkened in curves. This brings back the color you wanted for the curtain, and the rest of the picture remains correct. If you decide the curtain is too orange, reduce the opacity of the brush, and paint over it. You can do this with all different areas of the picture, each being a different layer mask.
Vincent Versace was one of the instructors at my course, and he is the king at doing what I attempted to explain above. He also sells DVD's on this exact process. You can check out his website at http://www.versacephotography.com/v2/
I hope this helps!