Hohner Bravo III 120 silent key

Nice Instrument sadly there is one reed constantly speaking when breath out (closing the bellow) on a cartain register I assume I was too impatient to try the instrument out and didn't let it warm up to room temperature, and also the dust protection on the treble side looks a bit inefficient that grid behind the grill looks so big that not prevent any biger particles of dust getting in the instrument, so a molino, or some more dense material as dust filter would have be a better option. I know I'll break the warranty but definitely I'd place some molino behind the front grill to improve dust protection.