Looking back
Looking back to 1968, 1969 and 1970 catalogues, it appears that this style range started out as something of a 'crossover' model that blended GE and Hotpoint cabinets and features. As I've stated before, I don't have access to a 1971 catalogue, so the first time I see this exact range is 1972. Prior to that, it was as if GE took the Mark 27 console, extended it 3" and put it on a Hotpoint range. Those ranges have the light switch on the oven door on the left side (always a Hotpoint feature), the oven door completely covers the cabinet (GE models had the cabinet extending to the front and the door inset between the side extensions), and there was a deeper space between the cooktop and the top of the oven door (similar to how Roper built their ranges). Since Hotpoint didn't always use the upswept cooktop, it was easy enough to install the separate console on the range. But by 1972 the cabinet was the customary GE version, lacking the upswept cooktop. Incidentally, in 1973/1974 GE began to phase out their old cabinets and went to the type where the oven door was fully 30" wide and the cabinet stopped behind the door.
With regard to the Mark 27, rear consoles were only added (and required) after these ranges could be fitted with the P7 oven. Until then, all controls were on the front of the range. But the operating controls for the self-cleaning feature required room so GE added the console to accommodate, and the result was a GE range without an upswept cooktop.
The biggest selling feature for the Mark 27 was it's supposed compactness (eventually loosing it's 'Mark 27' badge and being marketed as a 'Spacemaker' range). However, the truth was it really didn't save space as much as it wasted it. Once the homebuilding industry began to use pre-manufactured cabinets, which were built on a 3" module) these ranges still required 30" of space in order to align wall and base cabinets. They would require a 1-1/2" wide filler on each side of the range to make up the difference. Also, not only did they still require the same 30" width of a conventional freestanding range, but they lacked the traditional storage drawer. More wasted space. When the Mark 27 was originally introduced (circa 1960) kitchen cabinets were typically built onsite or in a shop for a particular installation, and thereby didn't waste that 3", but once manufactured cabinets became the norm, a lot of the perceived value of this installation was lost.
lawrence