Restore to stock rooted? topic

Hoping someone can point me in the right direction. Runnig CM12 and I'm jus having too many issues with critical components (battery life, phone, mobile data, bluetooth) a want to return to stock ROM but stay rooted so I can debloat and leave for future ROMS. When I first rooted I made a stock rooted TWRP backup but for some reason it fails to install and isn't listed under the restore option. What are my options to go back. Do I have to unroot, drop to 10b and then do the whole process all over again or am I missing something. thanks
Darren