This is a very easy question to answer. If you've sorted out the situation, then you let him know that you've taken care of the matter. I would say "h, thank you for offering to assist me w/locating the paperwork, but I've taken care of the matter".
There is nothing wrong in being honest w/him if you've taken care of the matter. It's how you respond/react to his offer. Actions speak louder than words.
Sit quietly, the answers will reveal themselves when you least expect them to. The past is gone, the present is a gift and you need to focus on today, allow the future to reveal itself when it is ready.
