I have seen those tubes go up for auction from our government,I have purchased many things here,they usually have a lot of tube testors,I have purchased expensive test equipment and other things here,you just have to keep doing a "search" every few weeks for "crt bulbs,electron tubes"I dont think they really know where to place crts,tubes in a correct area,sometimes you will see electron tubes come in a package with tire tubes.but from time to time you can find round vintage picture tubes,one time they had a bunch of those round zenith black matrix color picture tubes,.below is their link.
http://cgi.govliquidation.com/auctio...&convertTo=USD