Rear seat belt anchor plates, cutting up a rusty floor anyone?

Looking for rear seat belt anchor plates, don't care what year, aslong as they are factory a-body. I have two cars with no rear seat belt anchors, now we have a kid I'm looking to make them a bit safer. I would like at least 8 so I can do both cars if possible.
Does anyone know if they ever had rear shoulder belts as an options on the 67-76 darts? My cars do have slots in the rear dash that looks like they are for seat belts.
If you can take paypal and send them to New Zealand that would be cool, but I do have other options if thats a problem.
Thanks