Dear Iain and mid-60s Buick owners trying to be ready for anything,
Yep, Ruthy came with her original bumper jack, which I stupidly used the first year I had her.
Obviously not the first choice, but the bumper jack can be used without damaging the bumper if you are very careful. Back in the day, my Dad had bought a hydraulic bottle jack, but we didn't have quite enough clearance to get it under the axles. So we would use the bumper jack to raise the car just enough to get the bottle jack under.
I hope never to need it, but I want to get this bumper jack I've acquired working safely. If you have it and don't need it - no worries. It's the opposite that could be very disheartening! . . . .
Cheers, Edouard