Depends on the space available and angle but the two-hammer method can work, particularly with a second pair of hands on a lever bar if room. Working of a car from the ground outside is not ideal or fun (or sensible for later in your life).
Too late now, but in UK we have places that can make real steel springs for low cost that could outlast the car, they can be made to the size and rate you want or to factory, much better than the factory or replacements, I am surprised you don't have such places, as the UK has lost all it's skills but still has a few of these types of places around.
Great to have such a report/guide to such work.
I think the dampers must have been in a shocking (pun intended) state possible from when you got the car, as said there is loads of travel for a wheel to hang down a pothole. You thinking all old cars are slow and do not drive well is common to what others that do not know think which is why I always suggest where possible to try driving as many many good mechanical/electric examples of the same car before buy so that you know how well they could or should go compared to potential purchases. But life is all about learning and experiences, just that it is less expensive to learn from other people's mistakes, I have about six lifetimes of them for cars old cars alone. 😆