in the mid 60s I learned how to do color separations on a Hell Klischograph K 181 (1,100 kg). We substituted a coated plastic for the zinc plates. In our case the four resulting scans (CMY + Black) were contact transferred to film for the offset printing process. To evaluate the scan we created an overlaid four [Kodak made] colored test films...
The 'processor' for the K 181 was a vacuum tube filled cabinet (250 kg) with knobs and dials...
In comparison, using a modern day film scanner is a snap... not to talk about time savings ; )