My wife and I recently moved to an 1920's Craftsman-style farmhouse. It hadn't been lived in for about ten years, and there was a lot of stuff in the house that we needed to clear out before we could move in.
These cans were of particular interest; I found them in a decomposing cardboard box under the stairs and they were among the few that hadn't completely rotted through and disintegrated. I suspect that they were more than twenty years old when we discovered them. There hasn't been a Shop Rite supermarket in this town since 1983.
We made many other, somewhat less disgusting, discoveries as well. In the kitchen pantry, we found a jar of pickles that had been left on the window sill. Over the years, the sunlight had bleached the pickles to a pale, ivory white. And in the cupboards there were boxes of dried food mixes, detergents, and kitchen items dating back to the 1940's (we sold most of them to collectors on eBay.)