I received an invitation for the 50th wedding anniversary of a friend. His son had copied the original and then it was copied to an invitation and sent out in letter form. I took the image, from the invitation and copied it at 300 ppi. I then tried to clean it up. I made some progress but I'm a long way from home. I've tried Unsharp and High Pass as well as various blending combinations. Also used Burn and Dodge as well as the much maligned smudge. I used Blur as well. I do not have the plug- ins that I've read about.
Would someone have any suggestions as to how to improve the quality as well as the sharpness? I have PS CS.