Here Is link to all Latest download for One Plus One Official ROM and simplest Tool to Use

Recovery from here This one is latest 2.8.6.0
Latest Bacon Root tool-kit form WUG here 
Latest Cyanogen OS 12 from Here
Latest Oxygen OS From Here
Latest Usb Driver from Here

If you wants to go back Use Bacon root toll-kit to perform the Task For you.
Manual Link to Latest 11s Is Here
Latest fimware Download from HERE