Well, they're home with me for $40, one has a Peerless tweeter replacing the original one, the rest of the drivers are stock; they sound beautiful. They'll need Vintage-AR goo and I'll go through the capacitors. Now, I haven't' had the model Sixes for at least 15 years, but these seem a bit larger and sound more "there," probably due to the pair of mids in each (those mids look very much like the full range 4" ones in the KLH extension radio speakers). I'll post over in the speaker forum so I can get information on an original tweeter. But, wow, these are nice speakers.