For bulbs, the machine originally used #44’s. Most of us use #47’s as they run cooler, but are slightly less bright. All of the suppliers that you would get rubbers from will carry them.

The #555 flasher bulbs are only used in a couple of places on the backglass. The on/off is just to attract attention to the game. I no longer own the game, so can’t speak to how many the game uses. Not having them does not affect game play, they are just cosmetic/to attract attention.