Ethno yes, Miscellania yes, but what ?

[fernando]

I have posted this one long time ago and, despite (partly) favourable answers, i am not satisfied myself with the suggestion i brought of what this thing would be.
The proposal was that this is a pistol locker; the (optional) vent and orifice with the lock to secure the trigger guard and all that.
I have being paging small arms books trying to spot a gun that would fit in this case; only found one in a thousand.
I thought that, by re-posting it in this new section, would atract a range of members more motivated to crack this type of riddle.
It was bought in a local (Portuguese) street fair ... from a Galician seller; it might as well be a type of thing restricted to the Iberian Peninsula; i wonder

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