Don,
You have bad condensers. That is the most likely problem. Being from '78, that is enough years to warrant replacing them. I have a B version I put new condensers in as well as increasing the wattage of some resistors. The tantalums are know to go bad. A good quality, i.e. Nichicon ULD 47mfd 25V, electrolytic will replace them. I would mine to have Option 5 like yours.
Mark
