Contents Unknown

Unopened envelope, it looks like there's a card in there. No writing, no stamps, no postmarks.

Found in "The Official Alaska Cook Book - A Collector's Edition" by Sue Phelps. Published by Southeast Alaska Empire, 1969.

So, should I open it? Technically, it's not mail.

EDIT: I opened it. Here's what I found:

A thank-you card, looks like it was handmade as the illustrations are unevenly cut and pasted down.

-Click to enlarge photos-