Thanks for the input so far. Here's more info I found stamped on it:
Stores ref No. 88/1124 2666
Reflector Sight MK II
AM Serial No 5428/41
British Patent No 504845/37
The case has 2 ID tags on it. One looks original the other looks like it came afterwards but it's still an old paper tag. Has a leather handle, brass clips, wooden case. The case is open and I didn't do a good job of showing the lid.
Is it from a Spitfire? From my mother's collection. She was into European WW2 air war items but collected a variety of other WW2 and 1940's era items as well.



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I also have this one:
Us Army Air Forces
Gunsight
N-6A Type 24704A Spec No.
W11-107 ac-143(52) Order No.
E.A. Labratories Inc. Brooklyn, NY
What did this come from? Value?



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I'd like to sell both of these. I'm keeping some framed fighter plane prints and models for my son's room but I have no intention of keeping artifacts like this. I think they need to be in the hands of a collector.