Neat find. I would still send post cards to my kids that I picked up at the motels and drop them in the out going box when out on the road for two weeks or so in the 1990. Gone now are the days of sharing your lives and activities with just a handful of people in your network. Now you can reach out to 85% of the world population in an instant on what your doing and where you've been.
mojjax,
You may have a hidden gem or two. For example, if you have the 'full face' Franklin stamp ( I see two) in either a vertical or horizontal coil form, that stamp is rare. As you may know, a coil stamp has no perforations either vertically or horizontally. That Franklin stamp was issued in both vertical and horizontal coil forms as well as the fully perforated form as shown in your pic.
Don......
That's a great find in many ways, you could probably sell some of the postcards that show old swimming holes to many detectors that hunt water, great information for water hunting.
Possibly some of them may have written where they went for picnics and such. think outside the box for locating hunting sites it does pay off. One mans trash is another mans or ladies treasure.