I agree with Mike, that that rifle is worth considerably more than the standard Model 1886 and those are pretty valuable.
Just don't force anything in trying to take it down. IIRC, there is a lever on the magazine tube you pull out and turn (counterclockwise if at the front of the gun looking toward the butt) to unlock, then pull it forward. Then retract the bolt so the extractor is out of the slot in the barrel, and unscrew the barrel. Sometimes, due to old oil and dirt (or rust), this is not too easy, but take it easy and don't damage anything.
Jim