The originals are in the repository..as for backing up, not necessary after downloading stock of your choice.
Sent from my SPH-L900 using XDA Premium 4 mobile app
You mean this ?
http://rwilco12.com/downloads.php?d...Note II (SPH-L900)/Kernels/Stock (TW) Kernels
Also, can I flash this even if I am on a non tw rom ? I am on PACROM and had flashed Plasma kernel. Now want to go back.