Could this be what i was told it is?
 

A safety lock for a revolver !!!
Has anyone here seen something of the kind?

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INTERESTING. BUT DIFFICULT TO FIGURE.
ON SHIPS ARMS WERE MOSTLY LOCKED IN THE ARMS LOCKER. PERHAPS A CAPTIAN MIGHT HAVE SOMETHING LIKE THIS IN HIS CABIN TO SECURE A GUN WHILE HE WAS OUT OF HIS CABIN. THE THING WOULD NEED TO BE ATTACHED TO SOMETHING SO IT COULD NOT BE CARRIED OFF. IT DOSEN'T CONFORM TO OLD LONG BARRELED PISTOLS TOO SHALLOW AND TOO BIG FOR A NORMAL GUN BARREL. PERHAPS FOR A FLARE GUN?? :shrug: GOOD LUCK FINDING MORE INFO.

Thank you Barry.
Indeed difficult to figure.
I would in a first thought beleive this is not a gun lock; just trying to give it the benefit of the doubt.
Giving wings to imagination ...
The grooved back side of this wooden case could indicate it is to slide into some rail, like that of some armoury cabinet.
The central part of the cavity is wide enough to lodge any type of revolver cylinder. The upper part could also easily fit any type of trigger hammer. The lower part is indeed a bit narrow for the handle, but narrow handles also exist.
On the other hand, if the gun was introduced with its barrel towards the case interior, the handle wouldn't have to fit in, but only the trigger guard ... in this case the barrel being very short, or no barrel like a pepper box ... or a flare gun, as you hinted.