Hi Matt,
So sorry to hear that! If you bought it new from a supplier, then we should both talk with them to see if they can get you a replacement set of tubes sent out quickly. If you are in New Zealand, that might be a better option than shipping out to you from the factory. Please follow these instructions and request a new set of power tubes and internal fuses: How can I make a replacement part request? This will start the process, and we will get your replacement tubes out to you one way or another; Gil will be able to help you with that.
But in the meantime, yes, you can swap out the good tubes and internal fuses (note, the external fuses are specific to different voltage units—so don’t swap those).
See here for the full information about fuses: What fuses do I need for the Power Station PS-2 and PS-100?
I think you already know this, but here is how you change tubes and fuses: How do I change the tubes and fuses in the Power Station