I agree with Giuseppe and upgrade is the first thing that you should do after the DR is over.
If you ask me, this should be your DRP at the moment:
1) Install the SAV server back.
2) Get a copy of makedrop from Symantec. Another way will be to script it. You have to give the clients the new certificates and the new GRC.DAT file. No other change required in the registry.
If you have the PKI backup, then follow this interactive doc.
http://service1.symantec.com/SUPPORT/ent-security.nsf/docid/2005040513373748
I haven't worked on SAV 8 but I think it does not use the certificates.....Only the UDP......So only the GRC.DAT should do it.......
For the upgrade\uninstall issue with the password, you can open a new thread once you get the clients back.