It is a good idea to update Classifieds listings as it saves everyone time and often confusion even years later when the threads re-emerge as a new member hunts parts. It is great when they can see a result too!
To amend you can ... click on "Thread tools' at top RH of your Original Post in the thread. A pull down menu with 3 options appears click on 'Edit Title' and click in the text field near 'Title:'
Either type **SOLD** or **FOUND** at the start and save, done.