Matmob sent this to me, they write,
Eudunda is known as the valley of Hidden Treasures, so we thought it apropriate to have a few caches around the place! There are now 46 within a 20Km radius. We own the Eudunda P.O. ( postoffice)and cjpostie, postiegirl106 and Mabar all work for us. Maybe one day you will come over this way and find some of our treasures,
regards Matmob.
( they also listed the geocaches youcan find at or near each of the scenes in this postcard, now theres a few big hints)