I built these about 20 years ago, they are MTM with dual transmission lines. They still work but have lost the bottom octave and need rebuilding. The VIfa drivers are no longer available so it's really a redesign. The two small boxes are the external x-overs. I'm hoping to find an experimenter in the Seattle area to take this on because it would be nice to see them live on. Finding drivers to fit will be a challenge, but the Satori 5" is the right diameter with a small gap. It might be fun to make them active. They also work as is with subs. Below is a link to the original build site, amazed that it's still there. This offer if for pick up only and they are heavy.
http://www.nutshellhifi.com/Ariel.html
http://www.nutshellhifi.com/Ariel.html