Hi Philip,
Thank indeed your for your engaged research work.
I am sorry to say that the so called 1332 Chinese handgun is meanwhile known to be a fake - the shape of the cyphers is modern, so they must be a modern addition.
The other cited pieces I have not seen myself but as this is the European forum I confined both myself and my collection to this part of the northern hemisphere.
I posted the early Swiss pieces quoted by you on the forum some time ago. There is no doubt that the small stocked piece is datable around 1400, the hook being a working addition of ca. 1430.
Anyway, please note that the title of this my contribution clearly confines itself to
dated, which
per se excludes the Swiss pieces.
Let me point out that, in Europe, we generally hardly find any dated painting or any work of arts and crafts before ca. 1450! (tombstones in cathedrals excepted).
In the world of weaponry, and by the the staff of the leadimg museums, my 1481 haquebut barrel is acknowledged to be the earliest known dated European handgun (cannon barrels excluded); so could we agree on solving our discourse by replacing
the world's in my title line by
Europe's, o.k.? .
Best,
Michael