The CASE of The Mysterious Briefcase

I read in the paper last week that my friend Jamie's house had sold, and I called her - SO hoping this might mean they would move into a house within walking distance of us! Well, no such luck - but they ARE in town, which is much closer than where they lived before. She picked me up and took me to see their new place (NEAT 50's house with a fabulous view!), and when were walking through , I noticed a little briefcase sitting under a table in the entryway. When she spotted it, she was like "What the heck is this?" She asked her son where it came from. He had no idea, either. Hmmmm. Weird. So, she brought it over to the sofa and opened it up. What was inside? A little calculator, the key in it's original little envelope - and - wait for it ... two $50 bills!
She called her husband, and, come to find out, her husband had come home BRIEFly (no pun intended), and had left it there. A client had given it to him when he had remarked that his son might like it to use for a laptop or something. Well- and this is the odd part to me - neither of them had opened it up to see what was inside! I know! Well, when her teenage son saw the interior he said - "I'm not using that". So then I said "Well, if you decide you don't want to keep it, I would use it!" (And you'll be happy to know that the nice man was thrilled to get that money back that he didn't even know existed!) And yes, Jamie gave it to me! Call me quirky, but I love it!:

I want to try to do something with it similar to this , sold by Pixiegenne on etsy, or this, sold by JanesApron. Check out their items for sale! They may even have one similar to these for sale right now. I love what those talented ladies have done! I'm liking the idea of perhaps a Peter Pan theme. I don't really even know how to do it! But we'll see.