73 Duster rear top shock mounting point failure

I had the same problem with a Duster I had 35 years ago. Bone stock 318 car. The way your shocks are mounted is factory correct. I can't confirm it, but I think if the upper bolts are not fully tightened to spec, this is what will happen. The shock will move a bit every time you drive causing the upper mounting points to flex & eventually wear-out & break. I've had 4-5 A-bodies (3 Dusters) & this only happened on 1 of them. Your best bet is to weld in new metal were the trunk pan cracked, (I know it's kind of a pain) & make sure BOTH upper shocks are tight. Just my opinion.