I tried this, went nuts with it
Use a copper finger, aluminium is a waste of time, lousy thermal conductivity.
you will have to permanently butcher your camera, the peltier-cooled finger has to directly contact the CCD sensor.
What killed it for me, was condensation, very hard to eliminate.
Its all doable, apparently Houghys commercial mod works very well, but your in for a world of pain doing it youself, a real challenge.