Ok said slowly....
THE RECTIFIER PLAYS NO PART IN THE IGNITION. NOR DOES THE VOLTAGE RECTIFIER THEY ARE SEPARATE.
Your ig system consists of primary coil, points, condenser, secondary coil then the plug and thats it. Spluttering to a halt is 90per cent plug or points and condenser.
Have you checked the points and condenser esp the gap.. Condensers are not all that reliable. On my old points bike i fitted mine outside the mag.