33403-19155 N=20
33403-19175 N=22
Count the number of teeth on it, probably 20 or 22. It may have this written on it also.
But, you don't need the part number to go to Toyota and order a part of your Aussie car. But it can help.
Also, I think I have one of these gears here I can sell you. Toyota may charge $60.
The normal way to buy this sort of stuff is off a wreck at the wrecking yard. But I have bought them new also, usually for a rare JDM vehicle.