While the Registry was intended to match like serial numbered Sahara plaques of different denominations, it reached it's submissions saturation in March of 2004 and has NOT be updated since. It was launched several years earlier, but became a lot of work keeping it updated with every change of hands of listed plaques. Several Dealers that held a quantity of plaques, only allowed me to show serial numbers and mask their ownership. These can be recognized where the 'name de plume' has the initials MH. I have long since forgotten who they are/were, as I made no recorded notes.
So, while it is hard to use the Registry to affect contacting the correct owner(s), I have left it in place as a reference to the confirmed, known serial numbers.
Link is here: http://www.thechipgallery.com/plaque.htm