On closer inspection one of the case screws was a different type and through a loupe the others had been unscrewed so I disassembled it and found it had been broken by a previous owner. I had thought when Amazon Warehouse listed stuff as used it wasn’t meant literally. Anyway one reed has been bent and twisted so that it fouls the slot (? not sure of term) and has been left with a large gap so it only works when blown hard and then it rattles.
The other one is discloloured and well scraped as if a coating has been removed, this is the semitone flat one.
So I’m returning it. Beware if you see it for sale…!
Meanwhile I had some success with the Stagg 32 tuning so I might just stick with that for now.