Assign new author to existing page

We are setting up a new site and all of the existing pages were created by users with Admin roles. I’ve installed the Members plug-in and created a new role called Committee Chair. I edited the capabilities for Committee Chair to include edit_pages and read.

I created a new user (Test User 1) and assigned it the role of Committee Chair. I’ve been experimenting with turning on more capabilities for Committee Chair but can’t seem to find the magical one that will make Test User 1 show up in the list of possible Authors when I try to edit the author for an existing page.

The ultimate idea is that we’ll have a user name for each committee chair and that user will only be able to edit his or her committee’s page. The problem is how to get all of these existing pages assigned to the correct committee and keep the editing restrictions in place without having to start over from scratch.

Any ideas?