the old downwards stuff is def pretty hard and dark. Surgeon's tracks especially where really raw and cutting. Magneze and Badger Bite especially.

also good was the construct rhythm label. lots of good tracks from andreas kramer. featured other great records from Andre Walter aliases.

might also be worth digging up some old Marco Carolla and Gaetek. back in the 90s those guys used to bang it out pretty good.

those are some of the bigger names/labels i can think of so prob be easier to find than some of the more obscure stuff.

and yes... that old cold dust stuff was immense.