THE best armature rewinder is Tony Cooper in Brierley Hill (‘phone number 0121 559 2405) Tony acquired all the relevant machinery, tools and parts when Lucas closed their service dept down.
How the magneto is assembled without any reduction in magnetism is simple. It’s magnetised after assemby.
You stand it on a re-magnetising coil, switch the coil on, pick up the magneto a walk away backwards out of the magnetic field – making sure you don’t go arse over tip. See Roy Lambert, he has a re-magnetising coil.