I agree with KIn. You might even volunteer to detect these older resources' properties if you mention to them that you could be useful in finding lost jewelry and other personal items of sentimental value in exchange for keeping old toys, tools,buttons that you might recover. ( We never mention old coins).
Historicaerials.com is a popular map system many of us across all forums here use. Depending on what area of the country you live in, here in N.J., they have aerial photography going back to 1920, and topographical maps (listed below the years) for locating homes, cemetaries, houses of worship, out-bldgs, and schools.Using the slide feature, one can toggle back and forth between the older years and any year up to 2007. Just download Microsoft's silverlight when prompted, for full viewing (no cost). http://www.historicaerials.com. Enjoy.