Originally Posted by Reds Nd2
If someone doesn't know what they are doing, they can destroy the value of an antique by cleaning it. Even cans of furniture polish and carpet cleaner suggest that you first test in an inconspicuous area.
The worst thing you can do to an antique is destroy the patina.
I don't think theres anything really that old, it seems to be largely easily reproduced stuff like photos of the key members of the BRM (Rose, Bench, Griffey Sr, etc) nothing really awe striking like signatures. The pennants seem to be rather run of the mill stuff. The only exception to it was one that had all the 1990 Reds "signatures" on it.