Leon, might I suggest that you put this warning in the thread cardcollectorguru has on the Autograph B/S/T forum.
It's a thread looking for offers on 2 signed Clemente cards. With him looking for offers I'd imagine most of the dealings are going on in PMs or email. If this guy is a crook I'd hate to see someone get burned.
Here's the thread:
http://www.net54baseball.com/showthread.php?t=178629