I am trying to complete a particular world coin series. I have tried e-mailing all of the prominent auction houses in Europe, monitored all major U.S. auction house sites, online sales sites, online coin groups, and for years have been unable to see the few coins I am missing for sale or available. It is only on the NGC census I see some of the coins I am missing having been graded. My question is does there exist any way by which I can send an offer or message via NGC to the owner/submitter of those particular coins to see if they'd be willing to sell?