I just wiped out an entire shoot due to thoughtlessness. All that remains is the Lightroom 4.4 catalog, which contains medium-sized previews of the images. Is there a way I can export them, presumably as jpg's from the Previews.lrdata file, so at least I have those files?
Let's take a step backwards
Before you decide that you can only use the previews, you might want to try these steps in order
Thank you! Rob Cole's software is a great solution. I had basically tried everything you suggested: the only viable route for me would have been to use undelete software on a multi-terabyte drive, resulting in scads of files with meaningless filenames (MacOSX), and that wasn't worth getting into.
Thanks again, very much.