original bumper jack question

A lot of nice bumpers have been screwed up by a factory bumper jack. There was a reason a lot of folks carried a small hydraulic jack and a couple of pieces of 2X4 in their trunk in those days. It wasn't at all uncommon for one to go up and not come down requiring that the car be pushed sideways off the jack, or come down a few notches and then do the free fall thing.