Best Regards,
Bill Grimm
http://www.audiokarma.org/forums/showthread.php?t=170679&page=3
Chip,
Follow the above link to check out another thread where a fellow is looking for an identical tube. Apparently, you can rebuild your old one (if you have it) but those metal tubes are costly to do. There is a posting on that thread from someone who has an equivalent 19dp4. You may try contacting him. Good luck, I just had to go through bad picture tube hell, and it is no fun.
Wade
ps http://www.hawkeyepicturetube.com/
these guys will rebuild your tube.
Best Regards,
Bill Grimm