Hmm... I don't think I follow... Why do you think all the burden (time, cost) "tracking down the owner" etc. should be on me, while this is him who should be interested picking up his goods. He can easily check when address his internet order was delivered. He didn't do that in past 2 months...
We bought our house ~7+ years ago. In July this year, we received several packages from one of TV shops. The address was ours, but the recipient is the previous house owner. I called the TV shop customer service and explained the situation. An agent confirmed that the order was placed and paid...