very nice shotgun!
it all makes sense as a Paris proved gun.
1908 is likely the manufacturing date.
I note the L date code for the Bernard tube set. I think that this date code is early 1900, indicating that the tubeset had been laying around for a little while.
This gun bears no indication that it was made in Belgium, and I would vote for a GR shop made gun.
BTW, the Scott fore-end release is far more French than Belgian.
I am looking forward to seeing more pics.
Best regards,
WC-