The cabin crew rest seats are not saleable seats, but in an overhead rest area not accessed by passengers on both aircraft types.
Not true, there are crew rest seats at the back of economy on the 777-200 and usually non sold economy seats even on the 300 series.
If there are overhead rest areas available on the 777 then there are no seats in the cabin for flight crew either. The only time cabin rest seats are available (normally 11k) for flight crew are if there is a 'dog box' at the back of first class. Cabin seats are only allocated for specific sectors as labelled in the FCN.
Do try and keep up Count.