A friend of mine owns a pair of JR 149. They have an annoying system to connect the wires in the bottom, having to remove the base, which makes swapping cables or speakers in the system more laborious.
I've listened to them with different amps, from a 25wpc tube integrated to a beefy vintage SS Luxman. They sound good whatever you throw at them, their midrange is captivating. They lack some of the resolution and maybe airiness of more modern LS3/5 implementations, but keep that tight and right timbre-wise midbass texture of good closed speakers.
Considering their age and size they're amazing speakers, but if you want them to sound aloud in a mid sized room, you need quite some power to drive them.
I've been seeing units for sale from time to time at the Audiophile Candy's free ads site in the UK.