His first answer was, that he doesn't know much about Mullard tubes, but when I think, that these are faked ones, we may skip the deal - it's anyway a sale or return.
In the second mail he asked, whether the '3' in the production code possibly may indicate 1963 instead of 1973

In 1963 the Xf2 all still have been double getter.
Meanwhile he had pulled the photo off the ebay auction. But I've copied it at the right time and uploaded it to my server, where it still is. After he recognized that, he promted me in a third email, to pull 'his' photo off of my server, because he owns the rights on that photo.
But no! It'sw still there:
http://www.larry-amplification.de/pixs/ ... uad.fk.jpg
where it's seen, that the fake logo even is bad faked, the REAL shield logo looks quite different in detail, see here:
http://www.larry-amplification.de/pixs/ ... .xf2-2.jpg
Be alert with ebay!
Larry