The oven looks almost exactly like the one in my neighbor's house, which was installed in '65. However it is in Brushed Chrome, and has a window.
The one shown (Coppertone) is a standard clean version, and would likely be the least expensive wall oven GE offered at the time. The first few years of the P*7 wall ovens had no window(s); think they came out on the '67 line.
GE introduced this basic style sometime in '59, and used it until the early 90's, with some restyling along the way. The first versions ('59 & '60) had somewhat smaller windows, the same size as the original wall ovens introduce in '54. On that style ('54 - '58), it is rare to see a window. I don't think any GE ranges had windows until at least '57. Pulltostart probably knows exactly what model first had windows.