Read all of this mess but I seem to have entirely missed your point, or purpose of this thread at all.
I sincerely hope that, in your servicing of Lenovo ThinkPads, you do a better job than the bozo who tried to use a high-speed drill to retighten the screws on the bottom plate of my old, dear T40, when I sent it in for warranty work (bad sound card, logic board replacement), then insisted when I complained about it that the numerous deep gouges across the bottom, the stripped screws, and the crack in the replacement board caused by over-tightening were my fault. Ironically, that's when I decided I'd never get another Lenovo, and for that and other reasons, switched to Apple... while occasionally replacing worn keyboards, fans, and performing HD/memory upgrades to friends' out-of-warranty ThinkPads for cash on the side.