Today I was lucky enough (or so I thought) to catch an old train with PA-4 #841 on the head-end. The front storm-door window appeared to be very dark tinted glass that could hardly be seen thru in the tunnel. And the "railfan" window also seemed darker tinted than usual. I have never seen this before on any PATH equipment. Has anybody else seen it? I'm thinking maybe the front windows on this car had to be replaced at some point, and darker glass was used for the replacement windows?