Yes, that was a neat bit of research. The printed circular I have must be quite similar in design and certainly shares the slogan though the paper is close to newsprint quality rather than the card stock used in booklet covers that I have seen. Also a bit larger, measuring 15cm x 10cm.
I'll add to your postings, smauggie, and toss in a couple of covers from the beginning of that 10 year time frame that tomiseksj offered. Interestingly, the booklet of air labels was given as 1945 when the slogan no longer applied.

