This thread is like a written version of
The View...or so I've been told.
We have got to come to terms with honest paper conservation in this hobby. The TPG miinions are no-talent ass-clowns when it comes to finding out what has been done by someone well versed in paper conservation techniques, and this focus on letting TPGs tell us what is what is just silly once you see what can be done without detection in terms of removal and cleaning, like the Joe D (assuming, of course, that there weren't harmful techniques and chemicals used). Properly performed conservation is accepted in every form of fine art and antiques involving paper, except baseball cards and comic books. Here are some insanely great examples of what can be done:
http://www.lapapergroup.com/before-after.html
and here is what they've done with baseball cards:
http://www.postermountain.com/form/p...formatted/5137
Look at the Johnny Unitas RC or the CJ Cobb midway down the page.
But it ain't cheap. Even a minimal project will run $200 with a good conservator.
As many have observed here, you can make dramatic changes with good old H2O. Look at this photo of Kid Kaplan I cleaned up with water and some photo cleaner:
And I'm just an amateur.