Are the inboard and outboard mounting brackets riveted to the seat sliders?

Why not just drill out/cut off the rivets ... remove the mounting brackets ...

then remove and mount the corresponding brackets from your Ford bench seats on to ONE of the bucket seats.

You'll have to go back to the junk yard for 2 more bench seat brackets.

The ford stuff is already contoured for the floor of your Ford.

That way you will only have to alter the inside forward mount of the passenger seat. Everything else would be a straight up "drill a couple of holes and bolt in" install.

If you can't find 2 more Ford bench seat brackets ... I got a TWO SETS of them.

let me know.