I found a source from the late 40s and another from the early 70s. I’d love to learn more about this practice, any leads? Leave me a comment below – thanks!

Remember When We Stitched Our Phone Numbers Onto Our Sweaters? Oh, Yes ... That Happened.
“Carlisle Evening Sentinel – Sep 30, 1971”

Remember When We Stitched Our Phone Numbers Onto Our Sweaters? Oh, Yes ... That Happened.
“Modern Living, 1947”

Where was Meghan Trainor when these ladies needed her? Not born yet! I’ll just leave this here: