Hi Tia_c your in luck. we just returned from spain and bought to so many souveniers that we had some shipped!. while in madrid we bought and shipped a beatiful mirror from Artes toleadano across from the Prado. We dealt with "Cristina" and once we returned she stayed in contact until our shipment arrived. www.artetoledano.com/inicioc.asp?w=at&Idioma=en
Being the curious that I am, I looked up the company that makes the ceramic plates and found this: http://www.cearco.com/index2.html
you can try contacting them but am sure you'll need the style #, etc of the plate.
I also found a company that imports these plates out in CA. so try this as well:http://www.spanishplates.com/index.php
hope this helps,