Restore wp_postmeta from wp_posts

I was tasked to move a wordpress site from one hosting account to another recently. When I looked at the database to dump it, I noticed that it was half a gigabyte full of spam posts. There were approximately one-quarter of a million posts that were attributed to authors other than the legitimate author. Being that I only had phpMyAdmin to download the data, I could not get it all before the web server timed out, etc. I could have used a script to chunk the database into multiple downloads, but had been told I could go ahead and remove “some spam.” So before removing all the spam posts, I decided to delete all the spam postmeta first. I was using a subquery with an IN clause and accidentally used a “double negative.” To make a long story shorter, I deleted the meta data for all the legitimate posts. doooohh!

Now, the pages menu doesn’t even show up (well, it has blank spots!) Only a couple of the hundreds of posts show up under All Posts in wp-admin.

I was wondering if anyone could give me some clues as to what values I could restore to the wp_postmeta table to restore posts at least to the admin portal.

Thanks