Bob;
Go to a NAPA store and ask them for a dual socket wiring lead. I think it's part number 6251 or somewhere in that area. I got two from NAPA last week. They consist of two wires to the fiber board plate, another lower fiber plate and the tension spring. They will fit down inside your existing socket nicely. If necessary, sand off one of the little nibs on one side of the fiber plate to allow them to go in easier. Then, since your socket is for a single filament bulb, the indentations on the sides inside the your socket will be at equal heights but the dual filament bulb locking nibs are at a higher and lower height. Simply file off some of one of the brass nibs on the bulb and insert it into your original socket and turn to lock the bulb. The one longer nib will seat fine and the filed nib (if you didn't take off too much) will keep the bulb tight. I am doing this on some front parking lights of my '49 to make them park/turn. Good luck.
