If that bike is as good as it sounds, I would pay $4000, spend $1000 freighting it to Australia, and be extremely happy.
I'm envious of your situation where so many good bikes are going for a song, and even then some quibble over the price. Restoring a bike to that quality, again if it is that good, would cost upwards of $6000 considering the cost of chrome, paint, NOS parts, and particularly freight which can more than double the cost of parts.
Spend the $2000, be happy, and ride out the economic crisis - you'll do better than leaving your money in the bank.