John's Treasure Box

 is a metal box in Northwestern Scrapyard, containing:
 * Grognak the Barbarian,
 * U.S. Army: 30 Handy Flamethrower Recipes and
 * Guns and Bullets.

It requires a key.

Possible locations for the key:


 * The key can be found on a random Wastelander, who you'll find being attacked by dogs near Meresti Station and possibly other locations. He will also have a note leading you to the Scrapyard and the box.
 * On a body near Relay Tower KX-B8-11