[Zope] Re-add a disk-based product that was deleted

I have a disk based product that was not working. I manually deleted it from the product management interface in the control panel folder. Now I have anew version that seems OK, but I can't persuade zope to look in the Products folder and find the product again. Help! Of course, I could undo the deleteion but then zope will get mixed up between the old and new versions, I fear. Any ideas? Thanks, Greg