HDBR,
I have the K-260 horns and the manifolds. (I actually have 4 of those.) In fact, I have everything except the 10" mid bass drivers for the sub-squawkers. They're no longer available from Klipsch, but engineer Jim knows of a suitable replacement that is readily available. Once I get those, all I have left to do is build the crossovers. I'm still looking for original literature on this setup.
Tony