vBulletin version: 3.8.7
On the [url removed, login to view] page, in the Moderation drop-down menu at bottom of threads list, add a new option for moderators: "Remove duplicate ads"
When this option is selected, then this happens to the selected posts:
1. Each selected topic title is changed to: [Duplicate Ad Removed]
2. The contents of the 1st post (inc attachments) in each topic is deleted and replaced with a message in bold: "Sorry, your duplicate ad was removed." (this should be an editable phrase in admin)
3. All replies (if they exist) on each thread are soft-deleted
4. Each topic is closed - it may be closed already, so script should check this
That's it. We are thinking that, for a skilled vBulletin coder, this shouldn't take more than 2 hours?