Authenticity of GU/GW cards

[Pickles]

I have to believe this has been discussed before, but perhaps not recently (I have not found any threads on this)

I am trying to arrange a memorabilia collection (GU/GW bats, jsy, pants) to accompany autographs for various HOFers (mainly NYY) and have been watching the 1998-2014 secondary card "relics" market.

In particular, I do read the words on the back, and while some "guarantees" are very specific (Donruss 2002-2005, shows a picture of the bat or jersey...) some other tend to be what amounts to a denial ("the item listed is not from any specific period or game...) which can lead a cynic to believe that a "Babe Ruth game used bat card" is a card with a picture of Babe Ruth, possibly a MLB used bat, but it might as well be a 2014 game..... Card prices (Miller) do tend to refute this, as the Ruth/Gehrig GU/GW memorabilia has a higher price, suggesting that the majority of the public (the market) believes the authenticity.

It gets harder (as time passes) to get a firm "guarantee" or certificate form the companies, and, in some cases, with a lo of evidence to suggest the articles are not what they appear to be (Thorpe Giants Jersey, 2005-present) Some acknowledgement in the form of lower prices (constant supply, lesser demand) can perhaps be tied to skepticism, but this may be a "reach" as far as "cause-effect" go

So, after a lengthy introduction, can the readers recall details/anecdotes etc of suspect card based GU/GW memorabilia? Any words of caution for novices on the wording (ie tribute, etc) ?