There was a two headed, stacked searchlight signal southward on the Monon in 1957.
There is a picture of it in the 1995 Tour Guidebook (Pg 40) with other info on Reynolds.
No other signals appear to be visible in the picture other than a possible ABS signal in the distance. On the slide the indication was green over red or Rule 281 (#7).
It was taken from the cab of #5 with the back of the head of AR Manne, Engineer to the right in April, 1957.