Well I see this thread is on fire!!

I have the rifle in hand. There are two inspector marks * over P and * over M. Also the date letter f not cursive. So it appears this was made in 1927 which makes sense at the maker (Donckier) went out in 1938. Anyway, contrary to what the seller told me, it is marked "B PLOMB" so despite the lion over PV nitro mark, this is a NFB rifle. Bullet weight/charge etc. left for the user to determine I guess. Those Belgians copied the British guns but not their proof marking system.