[NoCmpromiz]

I didn’t know that Amtrak had gone to its own 2-lamp version of the 3-lamp position signals.

Yep.. That seems to be their choice as the upgrade to the PRR system. It at least preserved a large portion of the hardware thus lowering the overall cost.

NS on the other hand has chosen to upgrade to 'Darth Vader' style signals when they modernize signalling on their ex-PRR portion of the Conrail acquisition. (Note the one pic with the replacements in the background. That's on ex-PRR near Buffalo, NY.)

[Publius]

I’m old enough to remember the Washington-to-Buffalo train, and I’m old enough to have ridden the Northeast Corridor and the Philadelphia area commuter lines in the Pennsylvania Railroad days. I remember the Red Rattlers.