1959 Philco Predicta holiday

[Radiotronman]

I've been holding off restoring my blonde Philco holiday because I thought the 2.63v CRT was dead(21EAP4). I saw online from another restorer that 21DP4 crts were used in some models(6.3v). I figured I had nothing to lose as testing it at 2.63v tested bad and the filament seemed dim. So I tested it at 6.3v and it came up into the low, but good range after cooking awhile. I can't find any info on the CRT except the sticker attached below. If it were at 2.63v tube, wouldn't the filament have burned out quickly? Let me know your thoughts as if love to get this going. I've located a flyback I need, but I'm holding off purchasing it until I get the very info sorted out.