I'm a big fan too. Always good to see other fans of the Tau 7!
I also always wipe them off with an oily rag. And every now and than wipe some napier pellet lube onto a new bulb.
The very old Tau 7's had a different forestock by the way, it was prolonged.
Every now and than they come up for sale.
The Standard was for sale in Germany, Frankonia, early ths decennium, for 300 euro's new.
The Sport was about 400 iirc.
They didnt stock the match or silhouet.
I bought my Match in Canada!? from Cibles Canada Targets, and special ordered the Silhouet here in Holland.
You can buy Tau's directly off the Tau website nowadays. Far easier, ánd cheaper.
Just order it, and they'll get back to you with an invoice.
Its not very easy in tsjech, I know, but they dont reply to email very well.
I ordered my Tau 7 Junior, Tau 200 BT and Tau MK8 this way.
Some more Tau info:
http://www.citlink.net/~schattler/ar19.htm
(tgag are Tau importer)