Lol... Forty plus years ago. Not really many being daily driven wrecked and parted out now days either.
A lot of "A" body parts cannot be bought without a search and the world wide web today. Being that you can't just go down the street and expect most parts to be sitting on a shelf at a local retailer. I would say "A" body parts are somewhat rare and can often be hard to find depending on the item.
A while back I was working on a 93 Ford work truck with a 460 engine. Looking for a water pump locally. No luck at all from local dealers or parts houses, had to order online or special order. I was surprised that no one locally would stock a part as common as a 460 water pump. That truck was at least twenty years newer than most of our "A" body cars.