Jack, the problem I experienced was that considerable force was needed to pull the flywheel off, and the annulus attached to the flywheel which made the nut captive, was visibly deformed outward where the nut-flange pressed against the back of it. I have seen one of those flywheels with the annulus opened up completely so that the nut escaped. Hence, I think a method is needed for preserving vintage flywheels by easing the load on the annulus. I don't like any axial force being applied to the crankshaft as a whole, but of course a puller attached to the flywheel web itself does not do that.
If it had been a cast iron flywheel I'd have happily (and far more effectively) used a metal hammer on the flywheel rather than a rubber one, but not on a brass or even a steel one, for fear of marking it.
