Find a 1156 bulb socket...they keep em on the displays with hooks at your local auto parts store. The one you want has little teeth/prongs that hold the socket in the right size hole. Drill the socket hole out and slide the new socket in from the bottom. It should pop in. Be careful not to force it and mash the teeth/prongs.
I am running a low profile 1156 double fillament bulb in mine...it fits under the glass running light cover on a 41-46. Make sure you get 6V bulbs if running 6V...along with a 6V flasher. The system works OK.
For added safety, I would look at a set of very small LED lights to mount above the bumper, behind the grille. Most folks don't know to look at the top of the fender for your turn signal....but then most folks don't know how to look....
