open id and the old selector are legacy items that were never user friendly.
The recommended thing to use is Janrain as we use on this site.
When a user registers with Janrain the Open ID URI is populated on the user account and can be seen or edited from the manage users page and could even be moved from one account to another by an administrator. A random password is also generated upon registration but is not needed if logging in with Janrain but it could be used independently of Janrain to login if the user knows the password or gets it with password recovery.
If you'd like me to consolidate your accounts on this site I can do that but please email me privately with details of which email address you wish to use/keep and which to discard. Your other account which has your main purchase history appears to have an open id uri so that one should be able to login with Janrain or directly with the password.
joe [at] mojoportal dotcom