I think this may be the same person who has been selling the tubes for ages but it's worth a look.

http://cgi.ebay.com/NEW-VINTAGE-17HP4-CRT-TELEVISION-PICTURE-TUBE-B-W_W0QQitemZ220411768291QQcmdZViewItemQQptZLH_Defau ltDomain_0?hash=item335190ade3&_trksid=p3286.c0.m14&_trkparms=66%3A2|65%3A10|39%3A1|240%3A1318|301%3A0 |293%3A1|294%3A50