I have a model 51 fence charger, and the light finally burned out after 33 years. I have not been able to locate a replacement bulb, and there are no marking on the bulb base to indicated voltage. Can you help me locate this bulb? It's a double filiment bulb with nubbs that are equally spaced from the base as opposed to offset nubbs. It looks like an auto type bulb.
Thank you, Larry