@leadcrew, Interesting. I’ve designed and built a similar speaker configuration about 7 years ago. Same MTM woofer with AMT configuration in custom walnut enclosures, but with separate subs below. I run them today with dual mono block tube amps. A local chain asked me to produce them for sale, and not interested. Way too labor intensive in small production numbers. Did it just for fun.
When ESS Electrostatic Sound Systems was temporarily relocated from Sacramento California USA to Germany for a number of years (since returned), and the five patents on the original air motion pleated transformer design expired (2002-2007), a few German outfits over there started making their own variations of amt speakers. 5+ COs around the world still making variations of amt loudspeakers now. They do posses a unique sound particularly when paired with the right components, fwiw.