The date code makes it easy. Looks like phi, the code for 1961. This is reinforced by the 16-70 mark, which puts this barrel post WWII. And the controller’s mark, the least reliable evidence, in this case is clear: Charles Watrin, in office 1928-1965. In some cases, the barrel may have been made a year or more before the rest of the gun. I think that most often happened between the wars. http://damascus-barrels.com/Belgian_All_Proofmarks.html
Thanks Rudolph! That was the same conclusion that I came to but I wanted someone to verify my assumption.
Agreed, Rudolph is correct, 1961 confirmed by the “phi” here:- http://www.shotguns.se/html/belgium.html Sent from my iPhone using Tapatalk