For the blanks above the scan gauge, I believe that was a load leveling button and security button in the sequoia, which shares that same center console. That little cubby is also for the sequoia, that's where the mirror controls are. I believe the blank switch next to the tundra mirror control is for heated mirrors? Not 100% sure on that! and like your labels say those other ones are for seat heaters
Edit: do you have side curtain air bags? If not, the blank on the dash might be the rsca off button for trucks that have the curtain air bags, but our old tundra(2001) had fog lights and heated mirror switches there I believe.