Liege makers supplied guns for dealers all over the world.
The
lettre annale is indeed 1926
16.9 & 16.8 are the bores in mm.
It carries Smokeless Proof.
The chambers are 65mm = 2 1/2"
I've not seen that stylized 'P' - it could be Pire
http://www.littlegun.be/arme%20belge...0pire%20gb.htm
