We were supposed to be going to Panama, but ended up at the North Pole instead. We decided to make a post card to record the event.
I made the drawing shown below and ran the post cards off on a mimeograph machine. Every member of the crew was given only one copy and then the master was destroyed.
Each postage stamp was canceled with our North Pole cancellation stamp.
In theory this should make them a collector's item, but who knows?