I also do not see how New Zealand would just have handed over any weaponry to Australia during the early stages of the war without some deal being struck; be it in exchange for something else or "the clinking of coin betwixt Canberra and Wellington".
"New Zealand received none until after World War 1 when 20 Light Battery in Auckland and 16 Light Battery in Christchurch were each equipped with four howitzers. However, in 1926 instructions laid down that they be equipped for shaft draught only, and that pack drill was not to be carried out. (General Order 303)."
This surely does not mean that the 3.7-inch mountain howitzers were acquired in 1926, does it?
"Well worn" from training maybe?