A few quick pointers on digital image repair work these are the fundamental steps I use in fixing up my NASA posts although the principles would still apply to any image. Hope it is of use to you. Cheers.
Ok so the detail here is a bit thin on the ground but you are kind of restricted with content with the space you have to work with so I hope you all get the gist of it. As is the case with most big corrections, the chances of you getting the desired result in one hit are slim so dont be put off by this as more repeated steps/laborious mask cutting may be required (as was the case with this Atlantis launch shot). Or you might get lucky and it all gels together first time around you never know your luck. For irregular surfaces such as skin or fabric you may want to consider my flesh smoothing tutorial which works just as well in either instance and is good for artefact removal too.
I think Noise Ninja will be on my Christmas wish list Phil...thanks for taking the time to put this together and sharing it with all of us. Deeply appreciated by this soul :~)