Seat Bolts Rusted Through
I've got a '90 TC2000 (flat nose) 'Bird. When we pulled the seats out, a couple of bolts actually twisted off. Some were about half eaten through with rust and some weren't too bad.
I believe my bus spent most of it's life at an Air Force Base in Utah. Utah is a very dry state. For those living in the damper parts of the country, I'd give some thought to your seat mounts if you have left the seats in their original position. Just a thought.
Herb in Utah