Of course the EDID chip could be soldered on or overwritten if already present. The link describes how to do this.
It appears the LCD I was using either did not have an EDID chip or had
one without the information corresponding to the T60. The T60 apparently
has hardware that rejects LCDs without this information
https://github.com/bibanon/Coreboot-ThinkPads/wiki/Flexview-Screens.
This is disappointing, however I was able to get a new LCD, this time
with the EDID information, and now my T60 works with libreboot. These
days it is hard to get hardware that works solely for the user, but
libreboot is definitely a good step.
