Vinny,
I believe your best path forward ( to obtaining a top-shelf listening experience with a Lansing product ) is to set aside your JBL components for now and instead make an Altec M19 knockoff.
The sectoral/radial horn found in the M19 ( as flawed as I think it is ) still images better than any of the older JBL slant plates ( or potato mashers ).
You would need to make the cabinets
from plans posted at GPA ( or purchase cabinets from
VSR > which is the cabinetry outfit in Atlanta that GPA has partnered with ) .
- You'll also need to buy a pair of 811B horns in the used market ( typically available for @ 150. on eBay ).
The main components ( 416-8B woofer, 802-G8 compression driver, 1201-8a crossover ) are all available for purchase from
Great Plains Audio.