I have a 73 ventura that needs the rear seat complete with the steel backing plates that make a floor when folded down.

 

I'm not sure if they're the same, but I have a complete white vinyl rear seat from a 78 hatchback

 

I don't know if it will fit either but between the two of us we can figure it out. There are two studs sticking up from the floor at 41.5" center to center. There are also two pads on either side at about ribcage high if you were sitting in the seat that had strikers and they are 47 1/8th apart. If you have the strikers I could use them too. Can you send a few pictures to oakhillauto@Hotmail.com I would appreciate it.

 

The seat cushion is roughly 52" wide with bars for the floorpan-mounted attaching hooks at 28" center-to-center. The seat back is about 43" wide x 24" high. The seat back is apparently held by "J" shaped hinges on either side to two holes 10" apart. I could not find the hinges today, but I am sure they are around here somewhere. Because of the extreme heat today (and all week - they say!) I was unwilling to brave my attic, which is the most likely place. I know the steel cargo floor panel is there, too. The seat back does have a 9" carpeted steel floor panel attached with a piano hinge.
I'll send pics to your e-mail