Im a toyota master tech and the red o-ring comes only from the factory. Its for us to see if the oil filter has been changed. This way if someone brings a car in with a blown motor and they want it to be covered under warranty we can see if its been serviced.
The scary thing is i have serviced cars with 20k and they have the red ring filter:crazyeyes:crazyeyes:no:
Anyways you might be able to find them but thats what they are for and to my knowledge you cant buy them from toyota.