The agitator on my Simpson 164 washing machine is worn, so it doesn't move?

How can you expect an answer when we don't know where in the world you live? This is the internet and goes all over the world. Your best bet would be phone a local repair company or a local appliance sales shop and ask them where you can get Simpson parts from near you. Better still you can Google Simpson spare parts followed by your location and see for yourself what comes up.

Lincoln Appliance NZ
January 2017