Does anyone know who manufactures the extrusion?

I deal with most aluminium producers in my job... If it is Capral who make the extrusion it will be produced in Queensland and their road transort system takes it through Sydney to Melbourne then onto Adelaide. The only worry I have is their max lengths are usually 6.5m not 8m, this may cause issues, hence the trouble nickb had. Also they may only produce masts for the association once in a blue moon and will probably not have any in stock.

You may be able to arrange something through Capral if they are the manufacturer and have stock that is... if not then nickb's option may be the go. I would contact the National Association and talk to them regardless. I am sure they have shipped masts around the country before.