few days ago I've sent to lansing@audioheritage.org a German 1978 catalog of professional/musical instrument speakers that contain K series drivers, and a technical document covering the K series, similar to this one about the E's. I haven't received any reaction/answer until now, nor do I find it somewhere in the library. As I can't post in the Technical Reference branch by myself, I have to suspect there's not any interest for these?

Best regards!