villiers c12 1975 electronic ignition with points + update

hi all as the title says i have a villiers c12 1975 model no C12 20 - 01 with electronic ignition and points/ condenser all original , according to info all the electonic  ignition engines have an ''E'' at the end of the serial no mine does not ! , also the parts list shows just the coil and mounting plate with no points , the coil looks just like a two stroke unit with an HT lead and a LT lead which you would ground to stop it , on mine the LT lead goes to the condenser / points and another lead from condenser to ground via a stop switch , any ideas how to test the coil unit and how does this set up work  HELP UPDATE i now have a good spark , i think the engine has been standing for a long time and after a good clean up and a lot of spining over it all came back to life , both my magneto engines responded the same way .