Hello!

Searching the key words in your poster, I found a version of it in the Imperial War Museum's online archives. They state it was made by 'Northfield'. Some more Internet searching reveals that they mean James Northfield, who made many a propaganda poster for the Australian government during WWII. Although the poster in question does not appear in the linked archive on the James Northfield Heritage Art Trust website, I would trust that the Imperial War Museum is correct, and this poster was made by James Northfield. I hope that this helps. :)