There appears to be a Birmingham proof mark, and the gun was once of higher quality than the typical Belgian 'Parker' knockoff
If you would like more information, consider posting here
https://www.shotgunworld.com/threads...hotgun.423424/
We will need full size close up images of every mark on the barrel flats and just forward of the flats, and the action flats. There may be a maker's mark.
Certainly no attempt should be made to use the gun, but after cleaning the external surfaces it should be hung to honor your wife's grandfather. You might squirt epoxy in the firing pin holes to disable the gun permanently.
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