You push in on the back rest at bottom as you pull up on the seat from the crevice
Seeing as I have no idea what this means, I'll describe it in my feeble mind terms...
You need to push your knee into the front vertical face of the seat bottom. (at aproximately the quarter points, maybe a foot from the doors each side) This will 'unhook' the bottom front of the the seat bottom. Then the front of the bottom seat will pivot upward and you can lift it out. Like Bjorn said, the seatbelts may have just fallen down under the seat. There should be three sets of seatbelts for a '68 rear seat, unless a prevoius Owner removed them. If the seat hasn't been out for quite a while, you really have to press hard. I am always afraid I will tear the fabric because of how hard you need to press and lift.
Thanks for the info, this should help a lot. I always thought there were only 2 sets of belts in the rear seat, because that's all that is currently exposed. I don't believe that this seat has been opened up in the last 35 years, because if so, the previous owner, my father, would have uncovered the additional set of seatbelts. I guess I'll find out.
