I'm not totally familiar with the intricacies of what's great and what's not-so-great in Altec 604 drivers, but I believe these are good ones and a quick Google search showed up others of the same model type with better cabinets at $6550-$7550 the pair.
These have rough cabinets, but the drivers are apparently perfect. Worth looking into if you are anywhere near Buffalo NY.
The seller is looking for $999 the pair:
Anyway, thank me if you get them!
Russell
Ooops, nearly forgot the link!
https://www.gearslutz.com/board/gearslutz-secondhand-gear-classifieds/1103592-altec-lansing-model-17-604-8g.html