First post from a long time lurker.  I am getting more into the older hiwalls and came across this.  1887 low wall, .32 wcf, 28" barrel.  Repaired wrist.  Tang sight is a recent incorrect add, but I am curious about the following.   
Front sight, I have one on an 1886 just like it.  Barrel sight has 3 leafs...looks legit but new to me.  Under barrel is marked 1 which is correct, ebony tip on forearm, but there seems like a lot of shrinking ahead of the receiver.  The barrel is very plumb color, more of a rust blue. I have heard of a rust finish but not seen one in person.  No hole behind the trigger for a single set...is that correct for a gun this early?
I am buying this rifle as a shooter and I am trying to establish price.  Tell me if you need specific pics of something as I have more....I thank you in advance for all the knowledge here on the forum.

Something is wrong with that forearm.  It shouldn't have that gap there.  The trigger is a standard trigger so there wont be anything for the set trigger.  The finish on the receiver should be case colored but either the case colors have all worn off to grey and then started to turn plum or someone refinished it.  The front sight is a nice sight but it is not original.  You haven't shown the rear sight but is sounds like an express sight.  That was certainly an option at Winchester but the odds are that it is not original.

I can't resize the photos..I do but when I save they revert back.
here is the leaf sight and I am sorry for the size

I could certainly be wrong but I think the rear sight is original to the gun.  Neat.  You don't see many original express sights on a low wall.

Front sight is a repro, but the rear is old. No idea if it's original or not, but it's not a repro. The vernier tang sight looks like a repro, and likely purchased from the same place as the front sight.
The gun has the early high breech block, and the half octagon barrel is a nice special order feature on any 1885. Can't tell what stocks look like, but the fit around the action isn't in great shape. If it's going to simply be a shooter, the stocks may be glass bedded and repaired to make them serviceable. 
Hopefully it has a good bore, as relining it can cost funds that could go towards a better gun.

I have one of the three-leaf sights, and it's Winchester allright. I agree that the one you have there is a replacement for an earlier sight. The other two are new. It's hard to tell, but the photo of the muzzle looks like there's a ding in it that might take a recrowning to remove. I'd buy it if the cost isn't too high.

Looks like a dangerous "put together" to me.  Forward the address of the seller and I will get it out here to the wild lands of Montana where it won't be able to hurt someone.
Bob

another pic of the forearm gap