Then I came across this vintage pattern sheet that was my grandmother's.
If the envelope I found with it is its mate, my mom (by my grandmother's address listed) guesses the date to be 1943. The post mark was all of one cent. The pattern is a mail order item by Alice Brooks Designs, sent from the Household Arts Dept in San Francisco.
This is my favorite design. A simple single crochet.
It was war time, and this required people to use what they had. Here's a pattern for recycling stockings into a rug.
Rectangular braided design (there is also a pattern for the more traditional oval design), and pansy hooked rug.
Crocheted Squares design.