This is a shot in the dark; but, the blade on this one looks as though it may have once been part of a Norwegian bayonet. The blade on the model 1894 would have been around 367mm long, 19.5mm wide, and 5mm thick. It is hard to see due to the extensive acid damage, but there seems to be a machine made fuller running along the top of the blade which starts an inch in front of the guard and ends just before the hook (clip point). Originally the blade had a spear point with a sharpened spine. This one seems to have lost a short section of point, which was corrected by rounding the clip point all the way down to the main edge.
original model 1894 bayonet and rifle
see:
Kiesling vol 1#247, Janzen's pg 151-3 for sketches of the original bayonet.
n2s