It's been my daily driver for a long time, between 10 and 15 years now. John and I found a coppertone one of these one afternoon and he said we had to grab it. In his shop, he had a white over-under Amana with the combination oven in white. He figured that he was not going to do anything with it so we never even took the coppertone one off the truck, we just swapped the lift-up cooktop from coppetone to the white one and switched the coppertone oven door without a window to the black glass one with a window. It was in immaculate condition.
One very special thing about this combination oven is that it has Amana's variable power control for the magnetron. It pulses in seconds at less than full power. The three dials on the right side of the control panel work with very good directions in the cookbook for micro-thermal combination cooking. There is the large power dial which allows the power to be dialed down to such short pulses that it is really possible to defrost meat without cooking the edges. For the two smaller dials, the top dial is the microwave timer and the lower dial is the delay timer so that if you put a pound cake that would normally bake for 80 minutes in the oven, you set the delay timer for 35 minutes, the microwave timer for 5 minutes and the power control for medium and lock the door. The cake bakes for 35 minutes with just heat at 25 degrees higher than the recipe calls for to enhance browning then the magnetron is energized and the cake starts rising. You can see it rise with every pulse of the magnetron. Within 5 minutes it is done so the baking time is cut in half! The outside of the cake stays shiny and the cake is very moist. John has a customer in Greenbelt who had one of these at the time and he very kindly borrowed her manuals for me to copy.
John told me that no microthermal ovens are made by US manufacturers now. The economic disaster eliminated the market and many people who had them because they were installed in the house when it was built did not use the feature so it was dropped.
The most dramatic thing is how fast it can cook frozen french fries. I turn on the broiler and pull the fries out of the freezer. I pour them into a Corningware skillet, put them in the oven, lock the door and set the microwave timer for 3 or 4 minutes. Then the bell chimes, I turn off the broiler, stir the fries, then give them another minute under the cooling broiler element and they are done all the way through and crispy on the outside.