Hey Dave,
I was reading the docs and it seems to mee like adding authority_id was an error considering the initial design. Take a look: http://www.openacs.org/doc/parties.html
"The users table is a more specialized form of persons table. A row in users table represents an individual that has login access to the system. The primary key of the users table references the primary key of the persons table. This guarantees that if there is a row in users table then there must be a corresponding row in persons and parties tables."
So I guess the solution is to create a new table to map external authorities and usernames. I've also realized that there's a seding documento for external authorities authentication (http://www.openacs.org/doc/ext-auth-requirements.html), so we have to keep the requirements. I'm already working on something like this and I'll share with you when it's ready.
