I think the only way to get the "Director's Cut" of "The Keep" would be to coordinate a heist to steal the print from the located vault where I'm sure all the elements are just withering away. Michael Mann disowns this film and has pretty much been the one behind this not getting released properly for a long time. Maybe someday when "Mann" is no longer around or has a change of heart then some label could go searching and put it together. Kind of like what happened with "Nightbreed."
Would appreciate a myspleen invite if anyone can spare one.