These are Electrostatic Tweeter modules similar to the 1-30 units that my dad has.. Im not sure of the dates of production on the 65's..I know the model 1-30's were put in production in the early to mid 50's and ran in production into the early 70's. The 65 uses I believe only 2 esl units in a angled array enclosure to the 130's 4 units. Both were designed to be used as mid-range/tweeter elements handling frequencies of about 1Khz on up run in parallel with woofer cabinets for the low bass, as a hybrid full range speaker system. No crossover was needed other than the high pass filter built into the electrostat. AR, Bozak, Tannoy and KLH made several bass only cabinet models which were usually sealed enclosures. The JansZen units would fit into the upper part of the bass cabinet or sit atop the bass unit. My dad has the 130's presently ( and still after some 40 plus years!) along with the orig KLH Model 1 woofer cabinets he paired them with. At the time in about 1959, he used one speaker in a mono system, and then added a second when "stereo" became more common in a few years. Both JansZens models when paired with the woofer systems were unbelievably good sounding and were way ahead of their time. Arthur JansZen was a genius and offered a speaker of tremendously good sonics, backed by years of research and Military testing experience. Today, his son David continues the legacy of his father and has brought the company back and into the 21st century with a new and exciting model.
Every now and then you find a pair on ebay( the 65's usually more rare to find)..In fact at the moment a pair is going for upwards of $400+ !! That tells you how rare these are to find.
Look at my system to see some pics of the JansZen/KLH system.