Just inboard of the pinch weld at each corner there's a small reinforced metal piece that looks kinda like a nutsack. When the cars were new there were notches on the pinch weld to guide you. Of course 30 year old smashed pinch welds won't tell you.
This is where the factory scissor jack is actually lifting from, not the pinch itself.
When I jack up my car I put the jackstands there. Instead of the jackstand saddle facing left to right straddling (eventually smashing) the pinch, it cradles those things facing front to back, butted up against the pinch.