Dear RuG, thank you for contacting us. Unfortunately we do not have any HD 6950’s in our lab or RMA department anymore so we cannot check the dimensions and thickness of the thermal pads.
On the Overclock.net forum there is a useful thread on replacing the pads and thermal paste in HD 6950 cards: http://www.overclock.net/t/1323787/torn-thermal-pads-on-hd6950
Aslo, depending on where you’re from you can find a selection of suitable pastes and pads, for example at Performance PC’s webshop: http://www.performance-pcs.com/thermal-compounds
Hopefully this helps.