It appears the rear sight is a replacement, but if all else is original, stock isn't split or chipped, bore is good, and everything is 100% functional you can expect between $700 and $1,000 on this I'd say. Lower end if you want to sell quicker, higher end may mean it sits for a fair piece. Just bought one nearly identical to this for $1,050, but cleaner receiver & all origninal parts, plus a Marbles tang sight. I looked at a lot of them over past 6 months before moving on this one, and based on what I've seen I figured that was a fair, but not great price. Hope that helps a bit......
As always, your mileage may vary!