The admins have been great, doing all this manual data shuffling, and I emailed my info right after they made the announcement. However, they indicated that my stuff is simply gone, and it seems that is the case with many people. They put my registration date back in based on an ancient email I had from the registration confirmation years back from the old forums, and they added what I could remember as the last post milestone: 9,000.
I found some of my old posts, as well as Kelmo's, Rico's, Petra's, and others whose user info was not retrievable in threads from imported_users that we had posted in, and we appear as "guest". That appears to be all that remains of the many thousands of posts we made.
Something is weird with the search too, because I have found such posts, but if you do an actual keyword search with text strings from them, they do not show up in the search results.
-Skylark
P.S. note that just because someone's user name was imported, it doesn't mean the posts actually are accessible. As far as I can tell most of what was archived is not around. Some people show many thousands of posts with their imported user name, but only a handful may be actually on the forums when you search for their posts.