Someone out there read my mind and tell me more things I don't know about this ship I have been loving for 40 years. Maybe this is the wrong thread for that, but try it before a mod notices.
On MJ's drawings seen in The Making Of Star Trek
you can see what looks like a bow light on the forward upper saucer. Well, they never did install an actual bow light, but there is a circular hole there covered by a frosted translucent circle of plastic that allowed the f/x guys access to the bulb that lighted the three circular windows on the front edge of the saucer. That little circular panel is barely visible (if at all) in most shots seen from above, but it is indeed there.