Wow!
Welcome to
RP, Flashman - that's one heck of an image to start off with! You've done an excellent job for a first try.
I agree with all that's been said. You've gotten some great advice so far.
The one thing I would add to it is that the skin tone is a bit yellow and it has a sort of "thick" look to it.
I personally think it's important when doing skin to try to keep the highlights and shadows intact to give depth to the image. You've done a good job on the shadows, but your highlights seem to have been smoothed out and blended in quite a bit leaving the face looking kind of flat in places.
Also, it's hard to do a good clone job in areas with much damage in tight spaces just because there is so little good image to pick up from. It can end up looking choppy, or being off color because the area you're picking up from isn't a good color/density match for the area you're trying to repair.
I played with it for a while, and this is what I came up with (I only worked on the head and the background). I didn't use the clone tool at all. Before Photoshop, one of the basic elements for fixing an image was airbrushing. Though it's one of the most difficult and time consuming fixes to do, I highly recommend giving it a try since it often (still) gives the best results. And, with Photoshop, we have the added benefit of being able to add grain to an airbrushed image for a more natural look, which wasn't an option in the "good ol' days".
1. Selected background with pen tool and masked it out
2. Made a new layer underneath and filled with gradient chosen from original background colors. Added noise and blurred slightly.
3. Added drop shadow to original layer. Even at the highest blur setting, the shadow was too hard so I moved it to its own separate layer and did gaussian blur on it.
4. Made a new Normal layer on top of everything and started airbrushing (see the Airbrushing tutorial)
5. After painting/airbrushing the hair, used smudge tool on it and did some burning and dodging.
6. Added a curves adjustment layer on top and reduced the yellow cast slightly
7. Added a color layer on top and enhanced color on lips and cheeks
Good luck, and keep up the great work. I'm really looking forward to seeing your next effort....