Those are real beauties--nice job! What components are you using--alnico or ferrite? Brand new GPA or vintage Altec? Have you compared the Z19 to the original Model 19 crossover? Any comments as to audible differences or differences in how the two eq pots operate/interact with each other/affect the sound? Is the top (horn) compartment bolted to the bottom or is it permanently glued and screwed? Also, what are you doing for bracing?