Pete,
Would you care to give an opinion as to where this shotgun was proved? In the picture in your post the lower left hand proof mark looks like the Leige 'tower' symbol or proof marking. None of the proof marks are very distinctive I would agree. You may disagree with my view but if you do please at least give your own opinion as to where it was proved.
Harry.
There are no Belgian proof marks shown. That line is not a Perron. There is a Birmingham proof shown. Who the maker was, I do not know.
Pete