Just curious, do you want them for some audio project?
They were used as the horizontal output tube in just about every TV from 1946-1950 and are commonly available from tube vendors and eBay.
There are some being made by the Russians:
http://cgi.ebay.com/USSR-TUBES-Beam-...QQcmdZViewItem
I hope they don't catch on with the audiophile crowd and become outrageously expensive like certain other numbers.
