"Alas xOWEx tickets in Australia need to be purchased well ahead of time. "
I wasn't aware that it needed to be ticketed that far in advance ex AU; I thought it was around 14days before departure. See how long you can keep holding the reservations for would be my suggestion
You say that you have used a website to check; I would suggest giving BA a call since I have found that there can well be discrepancies
Dave