After some rough sketches of the design with pen & paper, I laid it out in Adobe Illustrator. Drew up a simple "safety ticket" background pattern, dug up some suitable fonts for the typesetting, and after looking at some period tickets for inspiration, it came together reasonably easily. It's not perfect, nor jaw-droppingly ornate, but it is completed. Printed 'em out on my cheapie little scanner-printer at home. Cut out with an X-Acto knife and perforated with a cheapie rolling cutter thingy from the craft store.
He's also made quite a number of paper props available at the Replica Prop Forum, including these outstanding classic era passport stamps. Sadly, membership in the RPF is a requirement of access to the paper props forum.