ThreeDollarBill,
Sorry I've not had time to get back to you on the other thread. When you lap your Celeron, you should start to notice the top getting somewhat shinier, and then you will start to see copper peeking through. Using successively higher grits of sandpaper you will eventually get a near mirror polish. Be sure to sand against something VERY flat like a sheet of glass... although to be honest, a nice desktop will do in a pinch. You may also notice witht the Celerons that the black plastic starts being removed at the corners of the chip... not to worry... it's normal.
If you do decide on an Alpha Heatsink, they are already VERY well machined and I doubt that further lapping would help you. On the other hand, I've had generic heatsinks that I just decided to give up on because the more I lapped the more I realized how HORRIBLY UNflat they were.
Joe