Actually, May of 1968 to May of 1971. From the picture is is impossible to tell if this is a pre or post soak-cycle KDS56. The soak cycle appeared sometime in 1969.
I remember in 1980, going to the library (I was 12) and checking out hardcover magazine compilations like Better Homes, from the 60s and 70s, just for the appliance ads.
I can remember this DW in numerous spreads, colors, cabinet styles, etc.