Well I think what we're trying to do is the impossible, and we'll have to simply restore the database to the beginning of the critical test. It was a good try, and we've learned a lesson about taking a full backup after a restore from another database. We've lost 2 full days of work, plus the day we spent trying to recover.

I thank you very much for all your advice and even though it was one of those painful lessons, learning it this way means we won't likely forget it.