By superimposing the 2 images we could see all the differences.
Apart from different swan, the decorations in the corners are very different, the background detail is different (random dots vs clear pattern) and the lettering is different.
Pretty much everything
Bobby De La Rue, I don't have the Mavis Pope book on 'Stamp Forgeries of Western Australia' but the website below attributes the forgery to either Angelo Panelli or Erasmo Oneglia (since Panelli was known to sell Oneglia's forgeries).
Click on the image of the forgery shown at the bottom of this page for an enlarged view:http://catalogue.klaseboer.com/vol1.../panelli.htm