Every original G-body headliner will need replacing on a car that old. As soon as you touch it...crunch crunch. That foam crumbles.
It's not a huge deal to change that out. But it points out that regardless of how well you keep your car, you'll need to restore it at some point to make it look new again. I'd worry about belts and hoses and coolant, etc. if that hasn't been changed. I assume so, but you never know. If they didn't recharge the A/C and flush the brake system just to be on the safe side, then, it's possible they hadn't done anything. And that would be bad. Those tires? Can't be trusted at higher speeds. Sorry. If they never moved the car, the flat spots may not fare well for those tires. I dunno, on one hand you don't want to drive it to death, but you do need to exercise them every now and then.