Hehe - yes, that was the Cadillac Eldorado convertible hood system. My car originally had that, but it was only designed to lift a fabric top so wasn't very powerful. The pump I am using now is a Smiths "Mini-Pack", which is famed the world over for being able to wake the dead, but was designed for use in truck tail lifts etc.
While not wishing to put it to the test, it should have enough power to jack the car off the canopy in an emergency!
It's funny, when you get out on the road you don't notice how low you are in comparison to other cars. My Nova measures 38" to the top of the canopy. If it was a Ford, it would be a GT38
(the latest Ford GT is a lot taller, which is why Ford dropped the GT40 tag)
Lauren