With respect to light bulbs, I have used 6v and 12v dual filament bulbs in dual filament sockets. The single dual-filament bulb socket in 1954 rear lamps was "ready to go" (a second lamp has to be mounted),and the front "parking lamp" socket was easily converted to a dual filament sockets.

With respect to the wiring, my wiring-setup would most likely not match yours (I have a 1954 GM truck signal setup with a 6-wire harness).

Have you checked out Cletis's Tech Tip on turn-signal wiring?