The nomenclature described for the subject rifle "Guerre" means "War", a pre WWII marking and earlier postwar, but not not conclusive. The receiver ring internal so-called "C" describing configuration of internal collar, would denominate either early or prewar action.
My 'opinion' an just that, of your pix, suggesting remnants of a clip guide rifle configuration origin. That might indicate a Transitional commercial FN rifle of latter forties which incorporated both solid wall and clip features! They are rare and most all are sidewall unmarked as sold to Husqvarna for build into their branded rifles. All FN commercial sporters from solid sidewall forward utilized the back-swept low scope type which became a functional FN brand feature.
Your pix, more likely indicates to me a welded fill-in sidewall. Z1R would be the expert there. (Also thanks Mr Z for that 'my bad' spelling correction in another Thread. :))
The bottom metal is aftermarket. 'If' the bolt is presumed original, its handle configuration could determine "Guerre" purposed origins or sporting.
Of course the net, net, simply what it is now. Origins perhaps interesting to speculate but value and utility what you make of it more than what is is. Perhaps "origins speaks most practically for "materials" as quality and if bolt original, such too.
Pix below of FN military actions, pre-war top, postwar below. As about same!
Good Luck!
Best!
John
