Has anyone dealt with JT Collectibles before? I'm considering the purchase of a game used bat signed by a minor leaguer (lots of signature exemplars, not so much on the GU end), and the bat is accompanied by a certificate from JT Collectibles for the autograph.

Anyway, my question, if you've dealt with them: Do they do witnessed certificates? The seller says they bought the bat directly from the minor league club and then had JT Collectibles get the bat signed for them.