Hello,
In your case, since I believe since the SEPM is installed on the same machine and the IP address and Hostname remains unchanged...I would suggest you follow this Article:
How to perform Disaster Recovery without Database backup/Restore
OR
Check this Thread on How to Restore Clients by simply adding the Domain ID to the SEPM.
https://www-secure.symantec.com/connect/forums/how-came-back-communications-clients
http://www.symantec.com/docs/HOWTO26639
OR
Use the SylinkReplacer Utility for SEP 12.1 (Available with Symantec Technical Support)
Create a Case with Symantec Technical Support for Sylink_Replacer_v.12.1 Utility and they would provide the same.
QuickStart Guide - Create and Manage Support Cases in SymWISE
http://www.symantec.com/docs/HOWTO31132
How to update a support case and upload diagnostic files with MySupport
http://www.symantec.com/docs/TECH71023
OR
Regional Support Telephone Numbers:
United States: https://support.broadcom.com (407-357-7600 from outside the United States)
Australia: 1300 365510 (+61 2 8220 7111 from outside Australia)
United Kingdom: +44 (0) 870 606 6000
Additional contact numbers: http://www.symantec.com/business/support/contact_techsupp_static.jsp
Hope that helps!!