Can any of you hook me with some resources to use when researching the authenticity of items that are being offered as "game used"? In particular, I've spent a significant amount of time trying to find information regarding NFL jerseys (e.g., the manufacturers, tagging, and other information associated with various teams and years) and MLB bats used by lesser known / obscure players, but I feel like I'm just beating my head against the wall. Any suggestions?