Battery life was fading after 2 1/2 years of service. And the other Iphone had a malfunctioning display (pixellines)
Replaced battery on one Iphone 3G and display assembly on another. All went flawlessly thanks to the great write up!
Ended up with one extra screw that fell out of one of the Iphones. There aren't any missing so I suppose this one rolled around somewhere in the enclosure...
For easy reassembly I printed out the layout with the location of the screws and placed every removed screw on the layout in the spot on the picture where it came out of the iphone.