Here's two things that I've noticed. The KitchenAid Superba dishwasher is actually a KDS-17A manufactured 1974-76 which added the Energy Saver No Heat Dry black button to the left.
The other one in this picture is a KDS-20C Series. You can tell by the control panel. The 19 Series light on the Dry was a No Heat Dry. The 20 Series brought back the Heat Dry Light and the Sani Cycle. Also, this series has the interchangable panels. And in the Sani Cycle, where it heated to 165F (74C).
On the 19 Series it lacked the Sani Cycle but heated the First Fill into Full Cycle to 150C and did the same thing on the last rinse.he 19 series did not. One other thing the Full Cycles on this dishwasher would heat the first Fill to 150F (66C). And the dishwasher the KDS-19C had no Sani Cycle.