The 'patented' peep sight on the bolt/extractor and reshaped Stock suggest this carbine was used by a 'Hunter'.

Likely the hand-guard, model 1896 rear sight and barrel-band, and sling-bar & ring were removed to increase handiness. The current barrel-band is a model 1899 carbine   band, put on backwards. (The "U" must be hidden on the left side).

Maybe the barrel muzzle area was heated up to knock off the original sight and some hobbiest never finished the project by installing a replacement ramp sight? That might explain 'blackened' wood.