That's right Tom!
I didn't think about that before yesterday and I had just one shelf in my 1959 40" range. The left ovens in 40" ranges is the same size as the lower oven and the right oven is the same size as the upper oven. Yesterday, I took a shelf from this wall oven to see if it fits in my 1959 range and it does. So now, both have a missing shelf but at least, I have one shelf in each oven until I could find two replacement shelves!