[Wymers Auction]

Are framing and matting under glass used to hide cut forgeries? The reason I ask is I was looking at a Lou Gehrig cut that looked awesome, but was authenticated by a well known authentication company that deals in forgeries. Are they so bold as to copy real autos and act like they are genuine. Is there any way I could tell the difference without having this in hand. Also I may add that this auction house deals in Marilyn Monroe, Beatles, Mantle, Darwin, Capone, Matthewson, and hundreds more all in the same sale. I am not worried if these items are authentic, but trying to learn to tell the difference if possible not having this in hand.