So I'm not the only one still holding on to a stack of those - now on number 2 of 3. Great (1600x1200) screen, great keyboard, sturdy, it even lasts a few hours on the battery - not bad for an almost 16 year old machine. Yes, a new mainboard would be good, I've been toying with the idea of stuffing one of the more performant SBCs in there (almost anything will outperform the 1.8GHz single-core Pentium-M in those things) but have not yet found one which can drive the screen.
I can get 8 solid hours of battery on my t42p with tlp and the schedutil governor. I also have a script that unloads the modules for certain hardware I might not be using that often. This is with one of those new Chinese batteries.
Absolutely beautiful machine. I am pretty sure it’s the greatest laptop ever built.