Thank you for your info AM! 🙂
I imagined it would be something for night fighters, since the reduced brightness of the “closed” position would hardly be seen in daylight.
So it would make sense to consider it a gunsight suitable for night fighter planes in general, or you know if there was another spec for it?
That’s very interesting, what I don’t get though is why there’s not range or selector.

Here are some pictures, I put a lamp under the body and managed to take some shots of the reticle as well.
As you can see, the box says one model, the main body another, and the reflector assembly another! So it’s either a Frankenstein gunsight or it was upgraded during its service life (if it ever had any?!).