Hi, firstly, my sincere apologies for not speaking German!...I will learn soon!
Although the burner is stamped 'Radium' I do not believe the burner to be a product of K&T at all...unless they took over from Hirschhorn...
This burner appears to be a rebranded version of a Hirschhorn 'Aida'.
Please check out this link;
http://www.be-back-later.com/forums/viewtopic.php?f=3&t=330
If you scroll down past the pictures of the HS Kronos 1911, you will see my rebranded 'Aida' imported to the USA and called a 'Liberty' with a larger collar-thread to accommodate the US fount threads.
You will also see the parts of the burner including the flame spreader which is very unusual, also the serrated air baffle that fits over the top of the outer wick tube...very Hirschhorn!,appears on their Carmen/Litenite lamp too.
There are slight differences in the body punchings but it has the same adjustment screw and the gallery raising key is the same design etc..the wavy lines on the burner base are very typically Hirschhorn too...
I will be interested to see if I am correct in my thinking!
All the best, and well done on finding a beautiful burner!
Cheers, Iain.