I pulled the red input and fired her up again tonight, and I can still see some red tint when I turn up the screen pot. I'm beginning to think the tube has a short. I'll have to get my hands on a rejuvenator if that's the case.
Since I received this tube in a cab with no chassis, I cannot verify that the tube is/is not bad, until I hook up a known working 25" chassis to it. This weekend I'll be repairing another 25" chassis that's compatible with this tube, so I'll test it to be sure.