They took the base fare prices off the oneworld website - reason unknown. Some people suspect the price removal may be due to a possible impending increase. The tickets themselves are still available for booking, they just no longer have the base fares listed online (though you can get a quote for a Oneworld Explorer via the online tool).
I have had no issues booking a RTW trip via the online tool from outside the country of origin (in this case, booked it to start in Japan rather then Australia).