You have to 'undelete' the corresponding row in tps_password table as well. It will be where tps_guid equals tps_password_id on the tps_user entry. See also the following article on undeleting soft deleted users: How to restore (undelete) a user which has been soft deleted
The authorisation error is probably due to the user not belonging to any role and hence no privileges.
Thanks Phil, you got it bang on!
All logged in and able to get back to the grindstone!