I realize that we're not answering your question - where to get it done - but to follow up on ifixcnc's post, I've done it a half-dozen or so times before, restoring some old prints (e.g., see the attachments for the original scan and cleaned up version of a nearly 100-year-old picture - this one is b&w, but similar principles apply). I don't know that I did it as well as someone who actually knows what they are doing, and I'm quite sure I spent a lot more time in trying things and then undoing them than a pro would - but the eventual results were pretty good, if I do say so myself.
Two main things that generally are needed when I have done this are 1) color and contrast enhancement - playing around with a variety of settings, and 2) spot erasing / copying - maybe something like airbrushing? - where I've covered over a spot in the print or filled in a broken bit by copying a part of the print with similar color and texture and dropping it in. Often I do this with a "brush" that includes a fade out to transparent; this prevents a hard-edged, obvious "repair." When I've done it well, the result is virtually undetectable without very, very close examination.
FWIW, I've used gimp (open source photo manipulation software) when I've done this.
Again, not really what you're asking, so I won't be offended if you blow this off!