Additional pictures from the owner
From the g it was proofed in 1928 (the golden age of Belgian gun making)
The blued barrel flats indicate that the barrels have been reblued, and may mean the casehardening has been redone.
The was marked for 65mm chambers (2.5 inch). It is possible they have been lengthened so you need to check. It they have not leave them alone. 2.5 12ga is easy to come by or load for. Those who shy away from it are wrong. I shoot a Greener 16ga FH-50 with 2.5 inch and it really is not a challenge at all.
Given your PM on your grandfather possibly purchasing from G&H or A&F you should check with Bob Beach at G&H as they may have records on SN 10019, which might contain more info on the maker if they imported it.
The barrels at proof weighed 1.352Kg (2.98lbs) if you weigh them and they are close you need not worry about wall thickness
On the engraving there maybe a signature or initials buried amidst the swirls.
I could guess at the maker, I am rather sure the parts were sourced from Britte, but they supplied many makers at that time.
It is a lovely gun
it is a lovely gun
