Deleted multiple sidebar plugins

After a classic schoolboy error on my part today, I have lost a plugin and can’t find it. I had the new site I was building in a dev area – when I moved it to the root folder and made the site live, I hadn’t noticed I hadn’t downloaded a local copy of a plugin.

The plugin was perfect for the site, when creating a page, on the right-hand side between the Publish and Page Attributes box (I think) I could choose to create a new sidebar. The I could go to the Widgets page and the new sidebar would be available at the right-and-side, and I could then just drag in the widgets I wanted. I had created two sidebars this way.

Now, I have two x “Inactive sidebar (not used)” boxes on my widgets screen and I cannot find what the plugin I used was.

Does anyone have any ideas of either a… what this plugin is, or b… a way of finding out what it was called?

Thanks in advance.