Dart Wagon 3rd Row Seat?

Hello all,
I am new here obviously so please forgive me if this has been covered before. I searched before making this thread, but came up empty. I am about to inherit a 1965 Dart Wagon. I am putting together a list of things that I would like to do. As it is, my wife and I are expecting our 6th child in February. I will be using the car as a daily driver and would like the flexibility to fit as much of my family as possible when needed. I know that just getting the right seatbelts is going to cost me, but I'd like to take things a step further.

So the big question is whether anyone has ever added a 3rd row to one of these wagons? If the answer is yes, then what seat was used and what sort of fabrication is involved? Am I insane for even thinking about this?