I figured the headliner suffered like the door cards do, where the humidity gets to them, over the years. It's never been garaged (it's last two owners both live in the neighborhood), and the last owner treated it like a beater, until it needed real work, and then parked it. It sat under trees for the last 4 years or so.

That said, is there a digital copy of TP30303/3 to be had? That would probably help save some time and cursing, as there are several little details about which the Haynes and Bentley books are lacking some. There is a physical one on eBay, though...