It all started in 1977. My best friend Nancy and I were knocking around downtown Portland, Oregon, where we attended college, and we wandered into the Greyhound bus depot, as one might do in those days. There was a rack of postcards, and I pulled out a 3-D postcard of The Last Supper. It became the first of a collection that has spanned four-plus decades and most of the continents. I don’t collect just any…