Would it be worth buying a spring compressor for this one job, especially from one of the high-buck tool distributors?
I wouldn't sweat the rubber spring pad as long as you have it, it's just a piece of rubber. If it's not damaged, it's up to the task.
I'm still more concerned about looking at the upper spring perch to make sure there isn't broke. If it is, a spring compressor is the least of your worries.