Lower cased d is the year code for 1925. The star over P is the controller of proof, however the records are incomplete for 1925.
Crown over R indicates rifled barrels. It was used from Jan 30, 1894 to Feb 26, 1968
10.1 is bore diameter ( I believe that is grove) which would be .39 caliber. This was done in .1 millimeter steps by this time.
B. Blindee used from July 8, 1910 to Feb 26, 1968; denotes rifled barrels over 22 caliber with bullets wearing a vest (chemise) aka jacketed bullets. Nothing about the type of jacket. The reverse of this is B.Plomb (lead bullets only).
At the time of proof the barrels weighed 1.716 kgs or 3.783 lbs.
The tubes were made by Jean Falla, his marks on this gun are; "Acier Compound CAP" also the squawking chicken, um screaming eagle, and Crown over JF.
The Crown over AF in a circle is Francotte.
Lion over PV is nitro proof.
I remember seeing the proof loads for rifles, but can't seem to find them at the moment. I do know that by 1921 the proof house was testing commercial ammunition in Belgium.
Sorry, Steve for not posting sooner. I am working on proof marks for other countries. Also converting a list of patents.
Pete
