G-Day Dave,
Yes, it is Australian made, MC is Munitions Cheltenham (Finsbury annexe) Adelaide South Australia, made in 1945. The stencilling on the side is very important in respect to the collect ability of the cart. This cartridge was filled @ MS, Munitions Salisbury (also a suburb of Adelaide) which was an explosives filling factory. Filled in September 1945. It used foil (lead), as a de-coppering agent, so the barrel did not foul after prolonged fire.
You have a very thoughtful daughter (better than buying socks & jocks for fathers day)! LOL.
The cart. case was used in the 25 pounder field gun, most widely used artillery piece by the Brits, Australian & NZ military in WWII.
Cheers, Ozzi.