Today I just finished the wiring on my 67. However some of the bulbs I recently purchased (#631 for the sail panel lights) didn't work because they are single filament bulbs and most of the wiring harness have dual filaments. I've been to several parts stores and they don't have the original style bulbs. I even went to Classic Industries but they don't carry them. Does anyone know where I can find these parts? Or do I already have the right bulbs but doing something wrong.