Hi, Larry!

I have to concur with you on this one.  Usually, when we update a search we didn't originally perform, we request a copy of the prior search so that we have a record of what was done before. 

We also specify on our final report to the client the time period covered, and that acceptance of our report constitutes an implied agreement to hold us harmless for any errors or omissions contained in the prior report.

Regards,
Scott Perry