While that cooktop was labeled GE, it was made by Modern Maid. I saw one in a new home in the 70s in NW DC. I was invited to go with a friend on a tour of Hillwood, the Margarie Post estate and after the tour, as we were going back down Linnean Ave., this new house was open for inspection. It was meant to be grand, but there were certain features lacking like the butler's pantry did not have its own dishwasher.
You will note that the cooktop only has one 8" element. When I asked John if it was made by Thermador, he said that the Thermador cooktop like that had two 8" elements while the Modern Maid only had one. With a powerful exhaust hood, the grill could be used with the grate to grill meats or it could be used with the griddle for that type of cooking, but it was not thermostatically controlled. As far as I know, there was no rotisserie for it.
Universal made a cooktop that was very much like the Thermadore in this configuration with two 8" elements.