I, too, bought a rebuilt. The shaft on mine was worn and needed a new bushing. Cost 5 years ago was $25, think they're up to about $40 now.
If you're installing an ignition module, the shaft needs to be checked. If it's loose, you will destroy the module.
If you go to rebuild one yourself, to disassemble it you need to remove the plate, then drive out a pin that retains the drive gear.
