Correct. I believe the D700/D3 was the last time Nikon made it's own sensor in DSLR. (which is why the D700 performs better than the D800)
Hm, Nikon didnt make own sensor sice days they produced JFET ones.
D700/D3/D3/D4 are Nikon own designs made by Sony. D800 is Sony made and designed. Difference between D800 and Sony 36 mpix FFs will be thanks to different electronics, CFA and AA. As it was with D300 and A700 or D7000 and A580.
Only Nikon 1 series sensors are not made by Sony. Maybe their compact line sensors too.