Nifty; this sounds like the sort of project you see recounted in talks at hacker conferences, complete with war stories of why the OEM did __ and __, and how it was successfully reverse engineered.
Suggestions
Since this is in the #hardware, not the #blog section, I think there is a bit more of an expectation to explain your acronyms for passers-by the first time you use them.
PM - Pentium M
NHC - Notebook Hardware Control
PLA (in context of CPU/RAM) - ?
ITP - ?
ULV - Ultra Low Voltage?
SBC - Single Board Computer?
Also, while I am a bit biased because of the time I put into researching my RAM ranks post it may help to link back to the memory thread you mention.
Questions
What are you using as the storage device, if these are IDE/PATA?
I too have an old laptop, and was about to buy a Compact Flash card to go with the passive PATA-CF adapter I have, when the main candidates, 128 & 256 GB Kingston CF cards began going up in price, and then semi-recently were entirely discontinued.
Anything else that fits PATA or CF seems to be at least 3× reasonable SSD pricing.