Sam, nice enough cover.
Interesting for the War time useage, the enlistment urging stamp, the Red Cross maniacs, the unusual postage cost of 2d to Canada, slogan cancellation and posted in an overseas box so commercial. Not to forget the medical aspect. Enlist and if you are wounded, this nurse will be attending to you, on a remote holiday destination.
At that date we had just lost the Battle of....
And the Buy it Locally campaign slogan seems to ignore the shipping losses to U-Boats while trying to feed Britain.
Now if only the cancel had tied the Cinderella (Fund raiser) to the cover, you would be celebrating more than the Melbourne Cup fanciers, punters and the bookies