I don't see why you had to go through all that work..? Were these full dumps or simply deltas? If they were full dumps and they were all on the same system whose clock was never changed then why couldn't you simply reverse sort the dir and pick the newest. If they are deltas, then wouldn't be easier to simply apply the deltas from oldest to newest?
Comment on Re: Optimising a search of several thousand files
They are full dumps. Picking the most recent file doesn't work because the dumps continued to be taken after the initial crash and restoration. So what I needed to do was find the last dump that was taken before the crash.