Good question about the visitor's ledger; would be cool. Will ask them.
I can speak to your other question, in that this is an official Topps Exhibit, so cards like a Cobb/Cobb or Ruth Rookie are not in the offing.
Do wish I lived close to see the other Topps cards and even the movie history pieces, but will be here in LA.
Also, here is a direct link to the Louisville Slugger homepage and the Topps Retrospective...
Louisville Slugger Museum Topps Exhibit