If I am asked to do an update on a search that I did not originally do, I require the prior search report.  If they give that to me, I add disclaimers that my update was conducted based on the information provided to me ONLY and add names and dates run.

If a client requests an update on a search that I didn't do and can't or won't provide the prior search, I let them know that it will be a current owner search - because that is bascially what I am going to have to do to find out all names  that need to be run and the legal and whether assignments, satisfacations, etc apply.  Without the prior search, it's a whole new search and that is what they are charged for.