As Beezermacc and Wozza say.
If you wanted, you could test for basic HT continuity by sticking a meter from the brass segment of the slipring to the mag body having removed a pick-up - should be a few thousand ohms. An infinite reading means trouble, probably because the coil is open line or, best case, is not connected properly to the slipring (or earth). At least you'd then know you had a real problem on your hands.
You should see the same K ohms from the contact breaker centre screw to the slipring, and should have (almost for sure will have), less than 1 ohm from the cb screw to the mag body with the points held open. This will show the low tension primary winding is OK and will also tell you that the coil is indeed earthed as both primary and HT winding are earthed in common.
Suspect you need to talk to Beezermacc!
