I've got a Lionel 0440 Signal Bridge and am unsure how to wire it up. I'm perplexed as it only has 4 sockets a head - I was expecting 5. Additionally, you can see it dosen't have any bulbs - I'm curious as to what bulbs it would take from the factory; I'm hoping they are yellow, or that there would be a frosted yellow equivalent. I'm just looking to figure out what the 4 terminals on each maroon base mean for each signal head. I'm likely not going to use the control panels but instead insulated blocks or O22 switch position to trigger the horizontal or vertical lighting of the heads.
P.S. I know this is technically a standard gauge item, but I'm going to sneak it on my O layout.