Will these steps also work?
Source - 126.96.36.199 on Windows 2003.
Target - R12.1.3 on Windows 2008 (64-bit)
Install R12.1 on Windows 2008
Complete Pre-Upgrade Activities on 11i on Windows 2003(32-bit)
Copy the 188.8.131.52 Application Datafiles from Windows 2003 server to Windows 2008(64-bit) server.
Apply the R12 drivers.
Upgrade Applications to R12.1.3.