I'm looking over the Altec Lansing papers on installation and assembly and Polarity and Phase by Ted Uzzle.
First principle is to line up the voice coils of the high and low frequency drivers in the vertical plane. All Altec small aperture compression drivers have their voice coil 1 1/2" back from the driver horn interface.
The JBL VC is approx 4 1/2" to the rear of the mounting flange.
Therefore, instead of the 2" recess of the 811B flange relative to the 2226 front flange (as the Model 19 design calls for)the 811B should be so far forward on the cabinet that there would be no way to secure it short of calling Nations Rent and getting a small crane!
Even the Martinelli Woodhorn projects 4 1/2" in front of the cabinet.
Does anyone know what the front to voice coil dimension is for the 416 woofer that would be in a true Model 19? Are the 2 driver voice coils in vertical alignment?