"the freewheel packed up" well, is there any way that a slipping pawl could have cause the problems that you have had ??
I (almost) always remove freewheels using the "destructive" method, as in removing the front plate, taking off the cogs, pawls and balls. Then removing the body using Stilsons and bolts wedged where the pawls would be. The problem is that the 2 tooth block remover, as shown often breaks, or breaks the body, before the threads give. It also gives a good opportunity to clean, examine, rebuild the freewheel mechanism.
From here, the inner plates of that chain look to be too close for the teeth on the block !?