I went with Robert Jordan’s photo. I can remember PRR position light signals on the SC&S line. Also note that this a Metra crew who has to be familiar with two different sets of signal aspects on the ex-MILW lines.
Balt, I grew up with the B&O CPL’s in Cincinnati and love them, but since I worked five years on the PRR, I lean toward the PRR/N&W position light signals. But I voted for Alex’s photo of the BN’s Zepher because I like the shearchlight signals and am so impressed by a museum that can take a train that is over seventy years of age, and safely operate it at it’s design speed, serving food and all that they did. UP, BNSF & Amtrak all had to inspect and agree for it’s operation. It is so much more than many stuffed museums do.