I went down and saw my brother Mark over the holdiay break.
Here are images of his system.
They are 4343's bi amped that has been through various incarnations over the years.
They were originally built in 1980 by yours truly in these boxes, then the mid/hf was taken out to reduce the weight for transport when used for shows. The boxes weigh about 200 kg each. The original 2231 drivers have been recone to the 2235 cone and are all original alnico. Mark also has a spare set of 2235h drivers. The crossovers use 12 db slopes and mylar capacitors. I've never measured the response but it sounds every bit a 4343.
More recently the Mid/Hf has been refitted and the boxes painted grey (previously matt black). The slot is front mounted and it appears to work very well. I could not convince him to reverse the slots to the outside.
The rack is all the original components over 25 years old, a 700B, a Quad 405 which Mark built on 1978, Nakamichi crossover and rumble filter and Teac CD & cassette decks. The Playmaster power amp series 3 in back is a recent addition as is the Playmaster preamp which he also built. He prefers to run single woofers these days.
This is a bachelor pad as you can tell, very neat.
Ian