Hello Fernando! Yes, a powder tester it is. I just couldn't remember the title for the thing!
No, 'Nando, that isn't a multi-barrel handgunne. It's just an antique curling iron!
Thought you might like some of his swivels and iron barrel guns. In particular that long 6 sided barrel standing upright in pic #13. What do you think? A handgunne or simply a barrel from a large musketoon?