Did you weigh the seats? I'd be surprised if it was more than 30lbs. The lower cushion is basically weighless, the seatback stuff is pretty light. I'll weigh what I have and will update this shortly.
The only thing left in the car now is the rear plastic trim pieces (on the sides of the interior/interior roof), the mentioned catches, and the full size spare/jack.
EVERYTHING else, (including ALL other brackets, and Torx screws) is GONE!
(I put large plastic body fastener 'push pins' into the empty Torx screw bores.)