Or just run it through some mediocre copy machines more than a few times.
Actually, I've noticed that with some yellow highliters, that if you highlight text then photocopy it, the highlit text appears more bold in the copy, with little sign of the yellow remaining.
"If you use something like Photoshop you could come close to faking it, but why not just go out and buy a Selectric for $75?"
If this guy is supposed to be such an "expert", why wouldn't it occur to him that the obvious way to change the boldness would be to xerox the thing a dozen times or so? Why didn't he mention that? I notice that he took the time to mention that people who disagree with him (I.E., YOU AND ME) might put a target on his back.
With a fax generation or something thrown in for good measure.
Look at the characters with horizontal serifs [e.g. on the letter "I"]. Notice that on the CBS decouments they are often concave on the outside. I don't know of any analog copier that would do that; it is much more likely to be a faxing phenomenon.
Whatever was used in at least one step of munging these documents to make them look old had a minimum vertical thickness [i.e. thickness of horizontal lines]. When something was too thin in the vertical direction, this device would attempt to place a minimum-thickness vertical line more-or-less centered vertically about where the original mark was.
Because Times New Roman has curved serifs which are thinner than the minimum vertical thickness, the curves on the insides of the serifs caused the whole serifs to appear bent.
I don't know what variations exist among fax machines, but I would think a forensic expert could probably determine which types of machines might have been used.